Schizophrenia has been identified as a disorder of the frontostriatal system with impairments in both sustained and selective attention (Bradshaw, 2001). The Sustained Attention to Response Task (SART), which required occasional withholding of an ongoing frequent response when a specified digit occurred, was completed by patients with a clinical diagnosis of schizophrenia (N = 52) and matched controls (N = 46). Relative to controls, participants with schizophrenia responded less frequently and made more impulsive errors. Their correct responses were slower on average, with greater variability in timing. Speed of response was unrelated to neuroleptic medication dosage. The slow responses exhibited by patients with schizophrenia were interpreted as reflecting primarily motor frontostriatal circuit dysfunction, and dysfunction of the lateral orbitofrontal/anterior cingulate circuit is implicated in poor impulse control. To address the heterogeneity of symptoms in schizophrenia, symptom dimension scores (positive, negative and disorganised) were used to determine whether symptom dimensions were associated with differential performance on the SART. Higher negative symptoms were related to increased miss errors on the SART whereas higher disorganised and positive symptom scores were unrelated to performance on this measure. An association between negative symptoms and increased miss errors may be considered indicative of dysfunction of the anterior cingulate circuit, considered to be linked to response inattention, apathy, reduced initiative and focused attention. Implications of this research for understanding the neuroanatomical basis for schizophrenia and its subtypes are discussed.

Dual task performance in children with Tourette Syndrome (TS) was studied. The participants were children with TS (N = 48, 40 male, 8 female), Attention Deficit Hyperactivity Disorder (ADHD; mixed types N = 44, 34 male, 10 female) and unaffected controls (N = 48, 34 male, 14 female). Eleven of the TS participants had no comorbidities (TS only) and they were compared to matched groups of participants with TS plus comorbidities (TS+), ADHD, and controls. Each participant was administered screening measures of behaviour, intelligence and verbal ability, as well as specific tests of dual task performance. Children with TS-only correctly recalled fewer digit span forward trials, and identified fewer spaceship pairs than controls under single task conditions in the SkySearch subtest of the Test of Everyday Attention for Children. However, the TS-only and control groups showed better counting performance while simultaneously searching for targets, than the TS+ and ADHD groups. Taken together, these results suggest that some previously reported cognitive deficits in children with TS are due to comorbidities, rather than to the syndrome itself.

Traumatic brain injury (TBI) is a leading cause of death and morbidity in children and can result in cognitive, behavioural, social and emotional difficulties that may impact quality of life. This study examined the impact of mild, moderate, and severe childhood TBI, when compared to severe orthopaedic injury, on behaviour as measured by the Child Behavior Checklist (CBCL) in a sample of 74 children with TBI and 13 with orthopaedic injury aged 4 to 13 years at the time of injury. Correlational analyses revealed that within the TBI sample increased anxiety/depression and somatisation were related to increased age at the time of injury and shorter inpatient hospital stay. Increased age was also related to increased parental reports of attention problems; while increased hospital stay was related to increased withdrawal and thought problems. Symptomatology was within normal limits for all groups, approaching the borderline clinical range in the moderate TBI group for somatic symptoms and in the severe TBI group for thought and attention problems. Those with severe TBI had more thought and attention problems, and to a lesser extent social problems, than those with mild or moderate TBI; while those with moderate TBI had the highest levels of somatic and anxious–depressed symptoms. The only scale where performance seemed to increase in relation to injury severity was the attention problems scale. It is suggested that the findings for those with moderate TBI reflect increased awareness of one's own vulnerability/mortality, with the implication that issues such as grief, loss, and mortality may need to be addressed therapeutically.

Most people only recognise the value of olfactory function after it is lost. In the context of traumatic brain injury with its far-reaching physical, cognitive, behavioural and emotional sequelae, posttraumatic olfactory dysfunction is an additional consequence that many survivors have to face as they adjust to a changed life situation. The aim of this article is to provide an update on posttraumatic anosmia for clinicians working in the area of brain injury rehabilitation. Brief reviews of incidence studies and causal mechanisms of olfactory impairment after brain injury are provided. Consequences of anosmia in the domains of safety, eating, personal hygiene, leisure, work and relationships with associated adaptive strategies are described.

Formal assessment of the impact of frontal-lobe impairment on social and interpersonal function has been somewhat neglected relative to interest in documenting executive impairment on nonsocial tasks. Despite this, experimental evidence is accruing that attests to the role of the orbitomedial frontal lobes, the amygdala and related structures in the appraisal and interpretation of socially relevant stimuli. In this address the evidence regarding the frontal lobes and social cognition, that is, social information processing is reviewed. At least 3 different constructs have been proposed that appear to be mediated by cerebral systems encompassing the orbitomedial frontal cortex: (1) social schema or social knowledge networks that guide judgments and behavioural responses, (2) emotional processing, including both the ability to recognise different affective states in others and the ability to experience affective (somatic) responses to emotionally important environmental stimuli, and (3) theory of mind – the ability to conceptualise what others are thinking and feeling. On the basis of this recent experimental work it is argued that a variety of assessment techniques are becoming available that are both practical and potentially sensitive to psychosocial changes after frontal lobe damage.