Chapter 16 Frontal Lobes Functional Architecture
Psychopathic Offenders: response control deficits in psychopathy VI: data from ERP studies
In summary, data from available ERP studies suggest that low socialization and psychopathy are associated w/altered processing of errors of commission w/in medial PFC and anterior cingulate structures, perhaps reflecting altered functioning w/in an extended circuitry associated w/the regulation of affect and behavior (Phillips et al., 2003).
Psychopathic Offenders: response control deficits in psychopathy IV: neural substrates & ERP – ERN
Evidence for the activation of neural substrates has been provided by brain event-related potential (ERP) (An event-related potential (ERP) is any measured brain response that is directly the result of a thought or perception. More formally, it is any stereotyped electrophysiological response to an internal or external stimulus.) studies showing that incorrect responses on a variety of sensory-motor tasks, involving multimodal sensory and motor outputs, are associated w/a response-locked negative potential (the ERN), which peaks between 50 & 150 milliseconds after an erroneous response has been made (Falkenstein, Hohnshein, Hoorman & Blanke, 1991).
Psychopathic Offenders: response control deficits in psychopathy V: ACC & left lateral PFC
Source localization research suggests that the ERN originates from generators w/in an area encompassing the anterior cingulate and medial frontal gyrus
and an area w/in the lateral frontal cortex (Dehaene, Posner & tucker, 1994). This interpretation was supported by recent event-rated functional magnetic resonance imaging (fMRI) study of performance of go/no-go task performance in healthy volunteers which demonstrated increased neural activity as measured by the blood-oxygenation-level-dependent response w/in ACC and left lateral PFC when participants erroneously responded to distracters (see Kiehl, Liddle & Hopfinger, 2000).
Using the Necker cube task (a visual illusion involving alterations in depth/figure perception), both Teuber (1964) and Cohen (1959) reported significant deficits after bilateral damage (http://dericbownds.net/uploaded_images/LatMedPFC.png).
caudal orbitofrontal cortex receives information from medial temporal cortical structures
The caudal (of, relating to, or being a tail. 2. : directed toward or situated in or near the tail or posterior part of the body) orbitofrontal cortex is richly innervated by cortical areas that support relatively late stages of unimodal visual, auditory, and somatosensory processes (Barbas, 2000; Carmichael & Price, 1996). Other afferents convey olfactory and gustatory inputs (Ongur & Price, 2000). Notably, caudal orbitofrontal cortex receives information from medial temporal cortical structures including the hippocampal-amygdala complex.
Because the straital targets (a striped mass of white and grey matter located in front of the thalamus in each cerebral hemisphere; consists of the caudate nucleus and the lenticular nucleus) (http://brainmind.com/images/brainslicethalamic.gif)
(http://en.wikipedia.org/wiki/File:Gray741.png) of these circuits receive input from cortical association areas, these circuits prove a mechanism for integrating information from various cortical sources and other cortico-straital-thalamic loops (http://www.csuchico.edu/~pmccaffrey/syllabi/CMSD%20320/images/U10ExtraPyra.JPG), which can be relayed back to the original cortical regions and/or output mechanism.
cortico-straital-thalamo-cortical loops involved in cognitive control by PFC
The precise functional significance of the cortico-straital-thalamo-cortical loops information remains controversial ( Robbins & Rogers, 2001). But, it’s clear that cortico-straital-thalamo-cortical loops are involved in the cognitive control mediated by the PFC. Studies have shown comparable impairments in the performance of behavioral tasks when lesions are made at different sites w/in the same loop (Goldman & Rosvold, 1972).
dorsal medial PFC & dorsal ACC = regulation of affective states
Involvement of dorsal medial PFC (http://empower2go.files.wordpress.com/2009/08/medial-prefrontal-cortex-music1.png) and dorsal ACC in the regulation of affective states is indicated by their involvement in error processing as indicated by the “error-related negativity” (ERN; Kiehl, Liddle & Hopfinger, 2000), the representation of arousal and uncertainty (Critchley, Elliott, Mathias & Dolan, 2000), attention to subjective emotional experiences (Gusnard, Akbudak, Shulman, & Raichle, 2001, and self-reflective thought (Johnson et al., 2002).
dorsal medial PFC = Lowered Blood Flow = anxiety-inducing stimuli
Activation of the dorsal medial PFC is specifically associated with lowered blood flow during exposure to anxiety-inducing stimuli (Simpson, Drevets, Snyder, Gusnard & Raichle, 2001) and induction of sad mood (Mayberg et al., 1999).
dorsal PFC = overriding attentional bias toward stimulus associations =ing reinforcement
Evidence for the involvement of the dorsal PFC (http://dericbownds.net/uploaded_images/FrontalRegions.jpg) includes findings that this cortical region is involved in overriding attentional bias (when a person does not examine all possible outcomes when making a judgment about a correlation or association) toward stimulus dimensions associated with reinforcement (e.g., Rogers, Andrews, Grasby, Brooks & Robbins, 2000).
dorsolateral & orbitofrontal cortex sensitive to neuromodulatory activity
PFC is richly innervated by the ascending arousal systems of the reticular formation, and there is now abundant evidence from experiments w/both animal & humans that the cognitive & emotional functions of dorsolateral and orbital sectors of the PFC are highly sensitive to changes in the neuromodulatory activity of the monoamine and catecholamine systems (Robbins, 1996).
dorsolateral & orbitofrontal cortex: dopaminergic, noradrenergic, central serotonergic activity
The ability to maintain information within short-term or “working” memory depends on dopaminergic modulation within dorsolateral PFC (mediated by D-subscript 1 receptor activity; Sawaguchi & Goldman-Rakic, 1991, 1991), whereas the ability to maintain memory performance under stress or distraction depends on noradrenergic action (mediated by Alpha-subscript 1 and Alpha-subscript 2-adrenoceptors; Arnsten, 2000).
By contrast, relearning stimulus-reward associations – a function largely dependent on the orbitofrontal cortex (Rolls, 1999) – is impaired by reductions in central serotonergic activity (Rogers, Blackshaw et al., 1999).
dorsolateral & orbitofrontal dysfunctions = impulsive personality disorders & likely psychopathy
Clinical evidence suggests that particular personality traits present in impulsive personality disorders (and likely to be shared w/psychopathy) are associated w/dysfunctions in dorsolateral and orbital sectors of the PFC systems (Coccaro et al., 1989; Soderstrom, Blennow, Sjodin & Forsman, 2003). Such association may be associated w/cognitive impairments, reflecting altered neuromodulation of PFC, but detectable by neuropsychological assessment.
frontal lobe damage = behavioral control impairments in delinquent & antisocial populations
Repeated observations that frontal lobe damage can be associated w/impairments in the control of behavior in both clinical settings (Meyers et al., 1992) and experimental settings (Hornak, Rolls, Wade & McGrath, 1994) have sustained neuropsychological research into the presence and possible importance of frontal lobe deficits in various delinquent and antisocial populations.
frontal lobe damage: perseveration, cue awareness & language deficiency
Milner (1964) and Luria (1969), who investigated task-specific changes in cognitive function following frontal lobe damage and reported a tendency toward perseveration (The tendency to continue or repeat an act or activity after the cessation of the original stimulus.) and a failure to use external cues to adjust behavior, as well as deficient verbal fluency.
Frontal Lobe Dysfunction & Neuropsychological Assement: inaccurate for frontal lobe dysfunction
The Wisconsin Card Sorting Task (WCST; Grant & Berg, 1948) or Stroop Color-Word Interference task (Stroop, 1935) are used to assess executive control functions and frontal lobe dysfunction. But impaired performance on neuropsychological tests is inaccurate and indirect guide to the presence of frontal lobe dysfunction. Frontal lobe damage or posterior cortical dysfunction?
frontal lobe dysfunctioning NOT = psychopathy -> Hare (1984)
Psychopathic offenders made more errors on the WCST and the SMMT and more spontaneous reversals on the Necker cube compared to both the nonpsychopathic offender group and the college controls. Gorenstein (1982) interpreted these results as support for the proposal that psychopathic offenders show impairments in frontal functioning. Hare (1984) successfully cast doubt on Gorenstein’s findings as a basis for inferring frontal lobe deficits in psychopathy.
frontal lobe function & regulation of affect I: anterior cortical system
Evidence for the involvement of the anterior cortical system (encompassing orbitofrontal PFC, insula, ventral striatum, rostrocinglate cortex, and amygdala) in the perception & appraisal of emotional stimuli includes findings that the ventral PFC represents the affective value of both primary and secondary reinforcers in relation to motivational states (Rolls, 1999), mediates learning revised stimulus-reward associations (Thorpe et al., 1983), and interacts w/amygdala to inhibit sympathetic autonomic arousal and defensive reactions elicited by amygdala stimulation (e.g., Timms, 1977) and the presentation of fear-conditioned stimuli (Sullivan & Grattan, 1999).
frontal lobe function & regulation of affect II: insula
Evidence of the the involvement of the insula cortex includes findings that lesions in this cortical area impair identification of official and vocal expressions of disgust (Calder, Lawrence & Young, 2001), whereas stimulation of this area induces perception of unpleasant tastes (Penfield & Faulk, 1955).
frontal lobe function & regulation of affect III: dorsolateral PFC & inhibition to aversive environmental stimuli
Support for the proposal that dorsolateral PFC, ACC, and the hippocampus support the regulation of affective states includes demonstrations that the hippocampal system (http://bernardbaars.pbworks.com/f/entorhin+=+paraHippocampal+system+-+good.jpg) is involved in both activation and inhibition of behavior in response to aversive environmental stimuli (Gray, 1982), & in the inhibitaton of stress responses w/other stress-related centers (Lopez, Aki & Watson,1999).
frontal lobe function & regulation of affect III: rostrocingulate cortex lesions = reduced aggression & emotional blunting
Lesions of the rostrocingulate cortex abolish autonomic responses to conditional stimuli & vocalized responses to painful stimuli, and can result in reduced aggression and emotional blunting (MacLean & Newman, 1988). As noted earlier, the orbitofrontal and rostrocinglate cortices interact, by cortico-straital-thalamic loops, w/ventral stadium in reward prediction & incentive-motivations SEE Schultz, Tremblay & Hollerman, 2000, for a review.)
frontal lobe: disruption of wider circuitry incorporating the PFC = psychopathy
The 1st-systematic investigation of the frontal lobe function in psychopathic offenders was provided by Gorenstein (1982). The rationale for this study: derived from analysis of behavioral changes observed following septal-hippocampal lesions (http://www.pitt.edu/~super1/lecture/lec2221/img015.GIF) in experimental animals, and the proposal that disruption of a wider circuitry incorporating the PFC may account for disinhibition to psychopathy and other forms of psychopathy (Gorenstein & Newman, 1980); Patterson & Newman, 1983).
frontal lobes = executive function integrity: contention scheduling mechanism & SAS = behavioral decision
Milner (1964) and Luria (1969), the dominant view has been that the frontal lobes are the site of a broad “executive” system that mediates flexible control of cognitive and motor resources for the attainment of distal goals (see Shallice, 1982, 1988, for a full statement of this position). Norman & Shallice (1986) content 2-kinds of control available to the “executive” system: 1) contention scheduling mechanism: stimuli contention; 2) supervisory attentional system (SAS): representations of the environment (affect representations) & of the organism’s intentions & cognitive capacities” & is able to activate or inhibit activity on the basis of the “best” contending decisions or Schemas (A schema is a cognitive framework or concept that helps organize and interpret information).
frontal lobes 3-sectors – PFC controls cognitive-emotional functions
Traditionally, the frontal lobes are divided into 3-sectors, a primary sector, a premotor sector, and a prefrontal sector (http://www.waiting.com/waiting.gifs/frontallobes.gif) – the PFC being proposed as being at the top of a hierarchy of control and mediating the most uniquely human of cognitive and emotional functions (Fuster, 1989). The cortical surface of the frontal lobes, accounting for roughly 30% of the cerebrum, consists of a number of subregions that differ in terms of their cytoarchitetonic properties (cytoarchitecture: the cellular makeup of a bodily tissue or structure and interconnections. The subregions have marked as well homologies and moderate differences, however, their functional significance in health and in psychiatric disorders, as psychopathy, remains an area of highly active and controversial research.
frontocortical surface interconnectivity – PFC controls cognitive-emotional functions
Sectors of the frontocortical surface have distinctive patterns of connections with other frontal sectors, with subcortical/limbic nuclei, and w/posterior cortical systems. These patterns of interconnectivity provide significant clues as to the cognitive and emotional functions subserved by PFC regions (Barbas, 2000).
lateral PFC connections: rostral cingulate cortex, brainstem reticular formation = oculomotor control-motor-arousal & attention
There are direct connections from the lateral PFC to rostral cingulate cortex (http://www.nimh.nih.gov/images/news-items/phelps-drevetsoptimism.jpg) and to the frontal eyefield, suggesting a role for this region of PFC in the control of gaze and overt attention (Passingham, 1993). Lateral PFC also projects to the major neurochemical nuclei within the brainstem reticular formation, consistent w/role in oculomotor control, motor planning, arousal and attention. p. 314.
lateral PFC: working memory maintenance
The SMMT (Sequential Matching Memory Task; Lezak, 1995) requires subjects to monitor a series of visually presented numbers and, on each trial, repeat the sign (plus or minus) of the number presented three places earlier in the series. It involves the maintenance of information within working memory and, in modern forms, has consistently been shown to depend on lateral PFC (http://www.floiminter.net/psychology/brain_and_behaviour/acc_pfc.jpg) function (Owen, 1977).
medial orbitofrontal cortex: connections control of autonomic & visceral function
Efferent (Conveying away from a center) connections from the medial orbitofrontal cortex project to the ventral striatum and the medial caudate nucleus as well as hypothalamic viseromotor centers (Ongur & Price,2000). These connections form part of a larger distributed network of neural stations – including the insula cortex, amygdala, anterior cingulate cortex, and periaqueductal gray – that is closely implicated in the control of autonomic and visceral function [the internal organs of the body, specifically those within the chest (as the heart or lungs) or abdomen (as the liver, pancreas or intestines] (Ongur & Price,2000).
neuromodulatory systems that influence cortico-straital-thalamo-cortical loops
Several cortico-straital-thalamo-cortical loops have been identified; including two linking dorsolateral and orbitofrontal areas to discrete striatothalamic pathways, and a third that originates in the ACC (http://www.glittra.com/yvonne/neuropics/cingulateparts.jpg). The functioning of these loops is influenced by several neural stations by neuromodulatory systems, including the mesocortical and mesostriatal dopaminergic systems, serotonergic systems and the cholinergic system originating in the nucleus basalis. ( Haber, Kunishio, Mizobuchi & Lynd-Balta, 1995).
neuropsychological test = frontal lobe damage in AB sample
Overall, the pattern of effects reported by Morgan & Liliefeld (2000) supports the view that marked impairments in neuropsychological test performance are evident in comparisons seen in various antisocial sample & healthy unoffending control samples
Orbital Dysfunction in psychopathic offenders I: tests to measure functions subserved by the orbitofrontal cortex
In a well-controlled study, LaPierre, Braun & Hodgins (1995) compared the performance of 30-psychopathic and 30-nonpsychopaths drug-free offenders on a battery of neuropsychological tests explicitly constructed to tap functions subserved by the orbitofrontal cortex. Measures of orbitofrontal cortex function: 1) go/no-go task (participants viewed a series of visually presented squares and crosses, and were required to make fast motor responses selectively to crosses having previously been trained to respond to squares), the error score on the Porteus Maze, and an index of anosmia (loss of smell) provided by the Modular Smell Identification Test (Doty, Shaman & Dann, 1984). The measure for dorsolateral PFC function was the number of perseverative errors on the WCST. Also administered: odor detection task to control for basic sensory deficits and mental rotation and block design tasks shown to be sensitive to right & left posterior cortical function , respectively.
Orbital Dysfunction in psychopathic offenders II: psychopathic deficiencies
Versus nonpsychopaths, psychopathic offenders exhibited significant increases in the number of errors of commission, but not omission, on the go-no-go task and qualitative rule-breaks, but not on quantitative errors on the Porteus Maze. Psychopaths were reliably less accurate at discriminating odors and showed a nonsignificant trend toward a greater number of perseverative (Uncontrollable repetition of a particular response) responses on the WCST. Psychopaths showed no significant impairments on either the mental rotation task or the block design measure.
Orbital Dysfunction in psychopathic offenders III: cognitive deficits mediated by orbitofrontal cortex
Taken as a whole (SEE: Orbital Dysfunction in psychopathic offenders II: psychopathic deficiencies article) the aforementioned pattern of psychopathic deficits provides encouraging support for the proposal that psychopathy is associated w/cognitive deficits mediated by the orbitofrontal cortex dysfunction. In the case of the go/no-go task, studies w/experimental animals & neurological patients indicate that lesions of the ventrolateral PFC impair performance of such tasks (Drewe, 1975; Iversen & Mishkin,1970). Odor processing is known to recruit neural systems w/in the orbitofrontal cortex, (Rolls, 1999), and lesions in this area are associated w/deficits in odor identification tasks (Johns-Gorman & Zatorre, 1988).
Orbital Dysfunction in psychopathic offenders IV: psychopathy =s cognitive & emotional dysfunction
Overall, findings of LaPierre et al., (1995) Roussy & Toupin (2000), Mitchell, Colledge, Leonard and Blair (2002), provide encouraging support for the hypothesis that psychopathy involves dysfunction in the cognitive and emotional processes subserved by the neural circuitry of the orbitofrontal cortex. Each of these studies used the PCL-R as the method for assessing psychopathy. In the case of LaPierre (1995) and Mitchell (2002) provide encouraging support for the hypothesis that psychopathy involves dysfunction in the cognitive and emotional processes subserved by the neural circuitry of the orbitofrontal cortex. In each case, deficits in psychopathic offenders were demonstrated on more than one outcome measure linked in some way to orbitofrontal function.
Orbital Dysfunction in psychopathic offenders V: orbitofrontal = emotional information
The orbitofrontal cortex plays an important role in representing emotional information and in a variety of motivational and reinforcement processes (Phillips et al. 2003). It is positioned w/in a distributed network that plays a critical role in affect. Its afferent projections allow it to integrate info from other parts of the PFC and from subcortical structures such as the amygdala that are critical for processing emotional signals (Barbas, 2000). Its efferent projections allow it to influence both autonomic reactivity and action selection systems.
orbitofrontal & dorsolateral cortex damage
Damage to the orbitofrontal cortex is associated w/behavioral and affective changes that might be related to antisocial personality and psychopathy (Meyers, Berman, Schiebel & Hayman, 1992). Orbitofrontal lesions induce induce pseudopsychopathy (thoughtlessness, impulsivity and disregard for social norms); lesions of the dorsolateral cortex induce a pseudodepression (apathy, lowered mood, and psychomotor slowing; Blumer & Benson, 1975).
PFC & cortico-straital-thalamic loop: cognitive control & affective regulation functions
The PFC uses identifiable circuits or “cortico-straital-thalamic” loops that have dissociable (distinguishable) functions in cognitive control and affective regulation (Alexander, Delong & Strick, 1986). Discrete (individually separate and distinct) areas of the frontocortical surface send excitatory (glutamate) fibers to the neostraitum [The caudate nucleus and putamen considered as one, and distinguished from the globus pallidus] (caudate, putamen [http://www.nyctreatment.com/img/Basal-caudate,thala,puta,globus.jpg]), which in turn sends inhibitory (GABAergic) fibers to globus pallidus/substantia nigra (http://www.profelis.org/amc/ap1/gifs/basal-ganglia_normal.gif). These nuclei project onto discrete thalamic targets. Finally glutamate pathways from these thalamic nuclei project back to the original cortical area to form partially closed loops.
PFC caudal lateral areas get & project sensory information
Caudal lateral areas of the PFC receive projections from visual, auditory, and somatosensory associations cortices from intraparietal and posterior cingulate (http://www.glittra.com/yvonne/neuropics/cingulateparts.jpg); and from the thalamic structures including the mediodorsal nucleus (Petrides & Pandya, 1999). Cortical afferents tend to overlap, so that this part of the PFC can process converging information from multimodal sensory systems. In turn caudal lateral PFC areas project to premotor and supplementary motor cortexes involved in the control of head, body and limb movements; the PFC does not project to primary motor cortex.
PFC cognitive capacity range II
Research indicates that the PFC plays a prominent role in an extraordinarily broad range of cognitive capacity, including pain processing and conditioning of anticipatory anxiety (Ploghaus et al., 1999); the representation of affective responses to primary and secondary reinforcers (Rolls, 1999); the perception of others’ mental states & aspects of social cognition (Frith & Frith, 2003); response inhibitory processes (Aron, Robbins & Poldrack, 2004); and the cortical representation of Spearman’s g. The g factor, where g stands for general intelligence, is a statistic used in psychometrics to model the mental ability underlying results of various tests of cognitive ability. Developed in 1904 by psychologist Charles Spearman to account for imperfect correlations in IQ tests, this model is considered the first theory of intelligence (Duncan et al., 2000).
PFC connectivity: plasticity promotes flexible response = conditional response
PFC cells exhibit a high degree of plasticity that promotes flexible links between input and output to facilitate the expression of motivationally appropriate behavior. Assad, Rainer & Miller (1998) reported that the majority of cells w/in the PFC were able to acquire patterns of activity that reflected the rule governing a conditional response (“if object A, saccade left”) rather than just the presentation of the cue or execution of the response (see also Thorpe, Rolls & Maddison, 1983).
PFC contributions to cognitive capacity range
Research indicates that the PFC plays a prominent role in an extraordinarily broad range of cognitive capacity, including (but not limited to) short-term spatial & object-based memory (Goldman-Rakic, 1987); encoding and retrieval processes in episodic and prospective memory (Burgess, Scott & Frith, 2003); control of attentional set (Dias, Robbins & Roberts, 1996); the initiation of voluntary action (Passingham, 1993); the representation of intention (Lau, Rogers, Haggard & Passingham, 2004); decision making under uncertainty (Bechara, Tranel, Damasio & Damasio, 1996; Rogers, Everitt et al., 1999);
PFC dorsal & lateral subdivisions for regulating affective experiences & modulating behavior
It is possible to evaluate what is known about the functions of circuitries involving different portions of the PFC w/view to postulating distinct but interacting functional systems. Phillips, Drevers, Rauch & Lane (2003) have proposed that a ventral anterior system – encompassing orbitofrontal PFC, insula, ventral striatum (http://www.mrc-cbu.cam.ac.uk/Lucapictures/zns0530858180005.gif), rostrocinglate cortex (http://www.glittra.com/yvonne/neuropics/cingulateparts.jpg), and amygdala – plays a predominant role in the identification and appraisal of emotional stimuli and the mediation of resultant affective states, while dorsal lateral system – encompassing dorsal PFC regions, the hippocampus and dorsal ACC plays a role in regulating such affective experiences and modulating behavior.
PFC efferent connections get feedack for maintanence of focus
The efferent (conveying away from a center) connections of the PFC are able to provide feedback to influence activity in other brain systems. PFC activity reflects the representation of goals that can be maintained over intervals when task-relevant stimuli are absent (Goldman & Rakic, 1987).
PFC mediates sensory inputs for executive functioning – neural pathway mappings
Milner & Cohen (2001) proposed that the PFC mediates (affect) representations of “executive” system & supervisory attentional system (SAS) & the action sequences needed to achieve them. These representations provide biasing signals of other brain structures so that the relative patterns of activity along neural pathways establish appropriate between sensory inputs, internal states (all kinds), and output mechanisms. Milner & Cohen identified features of the architecture and cellular properties of PFC that make it suitable for this purpose – executive function.
PFC supports anticipated events & expected reinforcers
PFC supports information processing relevant to anticipated events and the priming of output mechanisms. There is abundant evidence that PFC neurons code the expected size and valence of anticipated reinforcers and mediate choice between associations with these reinforcers (Tremblay & Schultz, 1999).
PFC-frontal lobes distinct cognitive processes few
Localization of PFC functions is controversial as there remain very few demonstrations of double dissociations (This is the demonstration that two experimental manipulations which-each have different effects on two dependent variables; the 2-experimental manipulations [two independent functions (double dissociation)] of distinct cognitive processes w/in the PFC or the frontal lobes more broadly (Dias et al., 1996).
Psychopathic Offenders: response control deficits in psychopathy I
The most theoretically developed account of response control deficits in psychopathy has been proposed by (Newman ,1998; Newman & Lorenz, 2002). In its most recent formulation, the theory states that self-regulation involves temporary suspension of a dominant response set and a brief concurrent shift of attention from the organization and implementation of goal-directed responding to its evaluation” (Patterson & Newman, 1993, p. 717). The mechanism that supports this shift of attention is mobilized automatically w/out active control and facilitates processing of contextual info as part of reappraising the current response set.
Psychopathic Offenders: response control deficits in psychopathy II
Response control deficits, or failure to activate a shift in attention means that psychopaths are not able to interrupt maladaptive behavior and regulate ongoing behavior. Criticially, the theory proposes that the core deficit is attentional and involves a failure to balance appetitive motivational states w/the regulatory impact of extraneous stimuli.
Psychopathic Offenders: response control deficits in psychopathy III: neural substrates
Little research has been done into the neural substrates of continued instrumental responding in the face of increasing punishment or into the neural bases of response modulation deficits in psychopathic offenders. However, these substrates are likely to include elements of the network identified by Phillips and colleagues (2003) as mediating regulation of affective states – namely, hippocampus and dorsal ACC.
neuropsychological tests – PFC pathways for emotional processing & regulation
Recent studies of psychopathy as defined by the PCL-R (Hare, 1991) is associated w/impairments that may reflect dysfunction in PFC pathways specifically implicated in emotional processing and regulation. Deficits include problems in response control (as indexed by go/no-go discrimination tasks; LaPierre et al., 1995; Roussy & Toupin), difficulties with selecting actions associated with uncertain rewards and penalties (as indexed by risky decision making; Mitchell et al., 2002), and error monitoring (as indexed by choice reaction time tasks and ERN, and the Newman card playing task; see respectively, Dikman & Allen, 2000; Newman, (Patterson & Kosson, 1987).
PFC pathways dysfunction – ventral system & dorsal system
These deficits (SEE: Summary: I: neuropsychological tests – PFC pathways for emotional processing & regulation article) suggest that psychopathy involves dysfunction in both a ventral system – encompassing orbitofrontal PFC, insula,, ventral striatum (those portions of the striatum located generally inferior to a plane representing the anterior commissure; includes the nucleus accumbens and some nuclei of the olfactory tubercle; may function in motor activities with emotional or motivational origins), rostrocingulate cortex, and amygdala – that identifies emotional signals and a dorsal system – encompassing dorsal,
hippocampus and ACC – that mediates regulation of affective states.