Beyond heritability: neurotransmitter genes differentially modulate visuospatial attention and working memory

A cued, visuospatial attention task and a working memory task were administered to 89 healthy adults genotyped for a T-to-C polymorphism in CHRNA4, a nicotinic receptor subunit gene. Increasing gene dose of the C allele of the CHRNA4 gene (i.e., no C alleles, one C allele, two C alleles) was associated with increased reaction time (RT) benefits of valid attentional cuing and reduced RT costs of invalid cues, but was not associated with working memory performance. In a second experiment, 103 healthy persons were genotyped for a G-to-A polymorphism of the dopamine beta-hydroxylase (DBH) gene. Increasing gene dose of the G allele of the DBH gene was associated with increased working memory accuracy at a high memory load. However, there was no consistent association between the DBH gene and visuospatial attention. Thus, a double dissociation was observed, with visuospatial attention associated with CHRNA4 but not the DBH gene and, conversely, working memory associated with the DBH gene but not CHRNA4. The results show that normal allelic variations in single neurotransmitter genes modulate individual differences in processing components of cognitive functions in healthy individuals.     

Inhibition of return in children with Tourette's syndrome and comorbid forms: a preliminary study.

BACKGROUND: This study investigated the nature and functioning of the visual-spatial inhibition of return (IOR) phenomenon in children with "pure" Tourette's syndrome (TS), and those with comorbid forms of TS. METHOD: Children with TS-only and "TS + comorbid" (TS + ADHD +/- OCD) and matched controls performed the inhibition of return (IOR) task, which involved responding to left and right visual targets appearing on a computer screen that were preceded by congruent or incongruent exogenous visual cues. RESULTS: The TS-only group performed similarly on the IOR task to the controls. When the TS-only group was subdivided into children with mild and severe TS symptoms, a post hoc comparison between the controls and severe TS symptom children revealed that these TS children had a reduced magnitude of IOR for targets appearing in the right visual field. The comparison between the TS + comorbid and controls revealed an atypical IOR pattern for the TS + comorbid group. They displayed a loss of normal facilitatory and inhibitory effects for right visual field targets. CONCLUSIONS: The findings suggest abnormalities in attentional "disengage" and "move" mechanisms in TS when directing attention to the right visual field, which may reflect left posterior parietal, superior colliculus, and midbrain pathology.     

Distinctive processing underlies skilled memory

Research on skilled memory has focused on organizational processes to the exclusion of item-specific processes, although theories of skilled memory do acknowledge the importance of both kinds of processes. Using the isolation methodology, we presented lists of American football team names to participants who had either a high or a low level of knowledge about American football. An isolation effect (greater recall of the target in the isolate list than in a homogeneous control list) was observed only with high-knowledge participants. When standard lists were used, an isolation effect was observed with both groups. These findings empirically validate the importance of both organizational and item-specific processing as the basis of distinctive processing underlying skilled memory performance.     

Human cognition and 1/f scaling

Ubiquitous 1/f scaling in human cognition and physiology suggests a mind-body interaction that contradicts commonly held assumptions. The intrinsic dynamics of psychological phenomena are interaction dominant (rather than component dominant), and the origin of purposive behavior lies with a general principle of self-organization (rather than a special neurocognitive mechanism). E.-J. Wagenmakers, S. Farrell, and R. Ratcliff (2005) raised concerns about the kinds of data and analyses that support generic 1/f scaling. This reply is a defense that furthermore questions the model that Wagenmakers and colleagues endorse and their strategy for addressing complexity.     

Atypical lateralization of memory for location: effects of deafness and sign language use

This paper examines the impact of auditory deprivation and sign language use on the enhancement of location memory and hemispheric specialization using two matching tasks. Forty-one deaf signers and non-signers and 51 hearing signers and non-signers were tested on location memory for shapes and objects (Study 1) and on categorical versus coordinate spatial relations (Study 2). Results of the two experiments converge to suggest that deafness alone supports the atypical left hemispheric preference in judging the location of a circle or a picture on a blank background and that deafness and sign language experience determine the superior ability of memory for location. The importance of including a sample of deaf non-signers was identified.     

Interval-timing deficits in individuals at high risk for schizophrenia

A duration-bisection procedure was used to study the effects of signal modality and divided attention on duration classification in participants at high genetic risk for schizophrenia (HrSz), major affective disorder (HrAff), and normal controls (NC). Participants learned short and long target durations during training and classified probe durations during test. All groups classified visual signals as shorter than equivalent duration auditory signals. However, the difference between auditory and visual signal classification was significantly larger for the HrSz group than for the NC group. We posit a model in which there is a clock rate difference between auditory and visual signals due to an attentional effect at the level of a mode switch that gates pulses into an accumulator. This attentionally mediated clock rate difference was larger for the HrSz participants than for the NC participants, resulting in a larger auditory/visual difference for the HrSz group.     

A family-based mental health program of recovery from state terror in Kosova

Family processes of communication, mutual support, and sustenance of cultural values can play vital roles in recovery from psychological and material damage in societies afflicted by terror. This is particularly the case when a campaign of terror has specifically targeted family life and its traditions, when the culture is one whose identity has been centered in its families, and when public mental health resources have been scarce. At the end of the 1999 war in Kosova, the Kosovar Family Professional Educational Collaborative (KFPEC) was initiated to counter mental health sequelae of war in Kosova. This initiative focused upon the recovery and strengthening of Kosovar families, rather than the psychiatric treatment of individuals for post-traumatic symptoms. Findings and outcomes from this project may usefully inform the design of other international public mental health initiatives.     

The impact of mental health evidence on support for capital punishment: are defendants labeled psychopathic considered more deserving of death?

Controversy surrounds the use of the Hare Psychopathy Checklist--Revised (Hare, 1991, 2003) in capital murder cases, where it has been introduced to support prosecution claims that a defendant represents a "continuing threat to society". Although widely presumed to have a prejudicial impact (e.g., American Psychological Association, 2004), little is known about how the lay public reacts to data derived from ostensibly stigmatizing assessment instruments such as the PCL-R. The present study examined the effect of psychopathy data on layperson attitudes by having 203 undergraduates review a capital murder case where the results of the defendant's psychological evaluation were experimentally manipulated. When expert testimony described the defendant as psychopathic, a much larger percentage of participants supported a death sentence (60%) than when testimony indicated that he was psychotic (30%) or not mentally disordered (38%). Interestingly, participant ratings of how psychopathic they perceived the defendant to be--regardless of the testimony condition to which they had been assigned--also predicted support for a death sentence. Given the limited probative value of the PCL-R in capital cases and the prejudicial nature of the effects noted in this study, we recommend that forensic examiners avoid using it in these trials.     

The collaborative assessment and management of suicidality versus treatment as usual: a retrospective study with suicidal outpatients

The Collaborative Assessment and Management of Suicidality (CAMS) is a novel clinical approach used to identify, assess, and manage suicidal outpatients (Jobes & Drozd, 2004). The results of a retrospective study evaluating the impact of CAMS versus treatment as usual (TAU) on suicidal outpatients are presented. Patients in the CAMS treatment group (n = 25) resolved their suicidality significantly more quickly than TAU patients (n = 30). CAMS was also significantly associated with decreased medical health care utilization in the 6 months after the start of suicide-related mental health treatment. These results provide promising preliminary support for the effectiveness of CAMS and a foundation for prospective research.