Skye McDonald

Brain Activity during Simulated Deception: An Event-Related Functional Magnetic Resonance Study

TheGuilty Knowledge Test (GKT) has been used extensively to model deception. An association between the brain evoked response potentials and lying on the GKT suggests that deception may be associated with changes in other measures of brain activity such as regional blood flow that could be anatomically localized with event-related functional magnetic resonance imaging (fMRI). Blood oxygenation level-dependent fMRI contrasts between deceptive and truthful responses were measured with a 4 Tesla scanner in 18 participants performing the GKT and analyzed using statistical parametric mapping. Increased activity in the anterior cingulate cortex (ACC), the superior frontal gyrus (SFG), and the left premotor, motor, and anterior parietal cortex was specifically associated with deceptive responses. The results indicate that: (a) cognitive differences between deception and truth have neural correlates detectable by fMRI, (b) inhibition of the truthful response may be a basic component of intentional deception, and (c) ACC and SFG are components of the basic neural circuitry for deception.

TASIT: A new clinical tool for assessing social perception after traumatic brain injury.

ObjectiveTo develop a clinically sensitive test of social perception for people with traumatic brain injury (TBI). DesignAn assessment tool comprising videotaped vignettes and response probes was developed in successive stages and tested on both normal participants and those with TBI. SubjectsA total of 169 normal adults and 7 adults with severe TBI (pilot studies), 283 normal adults, and 12 people with severe TBI (main studies). Main outcome measures“The Awareness of Social Inference Test” (TASIT) comprises videotaped vignettes of everyday social interactions and has three parts, each with alternate forms. The Emotion Evaluation Test (EET) assesses recognition of spontaneous emotional expression (happy, surprised, sad, anxious, angry, disgusted, and neutral). The Social Inference–Minimal (SI-M) test assesses comprehension of sincere versus sarcastic exchanges, whereas the Social Inference–Enriched test (SI-E) assesses lies versus sarcasm. In both SI-M and SI-E speaker demeanor (voice, facial expression) indicate the intended meaning of the exchange. In addition, the SI-E vignettes have other contextual clues that reveal the speakers’ intentions. Performance on SI-E and SI-E is assessed via four standard questions per item probing for understanding of the emotions, intentions, beliefs, and meanings of the speakers and their exchanges. ResultsGroups taken from the pool of 283 normal adults achieved a high level of performance on all aspects of the test with some influence from both education and intelligence. The 12 people with TBI were poorer at judging emotions than were matched controls, with particular difficulties recognizing neutral items, fear, and disgust. They were as capable as matched controls when understanding sincere exchanges and lies but had difficulty with sarcasm. ConclusionsTASIT is straightforward for people with a normal range of social skills while being sensitive to social perception deficits after traumatic brain injury.

Rating the methodological quality of single-subject designs and n-of-1 trials: Introducing the Single-Case Experimental Design (SCED) Scale

Rating scales that assess methodological quality of clinical trials provide a means to critically appraise the literature. Scales are currently available to rate randomised and non-randomised controlled trials, but there are none that assess single-subject designs. The Single-Case Experimental Design (SCED) Scale was developed for this purpose and evaluated for reliability. Six clinical researchers who were trained and experienced in rating methodological quality of clinical trials developed the scale and participated in reliability studies. The SCED Scale is an 11-item rating scale for single-subject designs, of which 10 items are used to assess methodological quality and use of statistical analysis. The scale was developed and refined over a 3-year period. Content validity was addressed by identifying items to reduce the main sources of bias in single-case methodology as stipulated by authorities in the field, which were empirically tested against 85 published reports. Inter-rater reliability was assessed using a random sample of 20/312 single-subject reports archived in the Psychological Database of Brain Impairment Treatment Efficacy (PsycBITETM). Inter-rater reliability for the total score was excellent, both for individual raters (overall ICC = 0.84; 95% confidence interval 0.73–0.92) and for consensus ratings between pairs of raters (overall ICC = 0.88; 95% confidence interval 0.78–0.95). Item reliability was fair to excellent for consensus ratings between pairs of raters (range k = 0.48 to 1.00). The results were replicated with two independent novice raters who were trained in the use of the scale (ICC = 0.88, 95% confidence interval 0.73–0.95). The SCED Scale thus provides a brief and valid evaluation of methodological quality of single-subject designs, with the total score demonstrating excellent inter-rater reliability using both individual and consensus ratings. Items from the scale can also be used as a checklist in the design, reporting and critical appraisal of single-subject designs, thereby assisting to improve standards of single-case methodology.

Weak coherence, no theory of mind, or executive dysfunction? Solving the puzzle of pragmatic language disorders

Deficits in pragmatic language ability are common to a number of clinical populations, for example, right-hemisphere damage (RHD), Autism and traumatic brain injury (TBI). In these individuals the basic structural components of language may be intact, but the ability to use language to engage socially is impaired. Despite the nature of these difficulties being well documented, exactly what causes these difficulties is less clear. Furthermore, the current status of causal explanations for pragmatic difficulties across these populations is divergent and sometimes contradictory. This paper explores the empirical validity of three theories that attempt to explain pragmatic language impairment. It is recommended that a new, more convergent approach to investigating the causes of pragmatic language disability be adopted.

Reliability and validity of The Awareness of Social Inference Test (TASIT): A clinical test of social perception

Purpose. The Awareness of Social Inference Test (TASIT) is an audiovisual tool designed for the clinical assessment of social perception with alternate forms for re-testing. Part 1 assesses emotion recognition, Parts 2 and 3 assess the ability to interpret conversational remarks meant literally (i.e., sincere remarks and lies) or non-literally (i.e., sarcasm) as well as the ability to make judgments about the thoughts, intentions and feelings of speakers. This paper aims to examine TASITs reliability and validity. Method. Some 32 adults with severe, chronic brain injuries were administered Form A twice, one week apart. 38 adults with brain injuries were readministered alternate forms over a period of 5 – 26 weeks. Construct validity was examined in subsets of a sample of 116 adults with brain injuries by relating TASIT performance to standard tests of neuropsychological function and specific social perception measures. Results. Test-retest reliability ranged from 0.74 – 0.88. Alternate forms reliability ranged from 0.62 – 0.83. TASIT performance was associated with face perception, information processing speed and working memory. Socially relevant new learning and executive tasks were significantly associated with TASIT performance whereas non-social tasks showed little association. Social perception tasks such as Ekman photos and theory of mind stories were also associated. Conclusions. TASIT has adequate psychometric properties as a clinical test of social perception. It is not overly prone to practice effects and is reliable for repeat administrations. Performance on TASIT is affected by information processing speed, working memory, new learning and executive functioning, but the uniquely social material that comprises the stimuli for TASIT will provide useful insights into the particular difficulties people with clinical conditions experience when interpreting complex social phenomena.

An Exploration of Causes of Non-Literal Language Problems in Individuals with Asperger Syndrome

Individuals with Asperger Syndrome (AS), a high functioning variant of Autism, are often noted to possess intact language ability, yet fail to use this language capacity to engage in interactive communication. This difficulty using language in a social context has been referred to as a deficit in pragmatic language. In particular, difficulty understanding non-literal language devices, such as irony has been observed. This paper examines the veracity of two theories that have attempted to explain the causes of pragmatic language difficulties in individuals with Asperger Syndrome; the theory of Weak Central Coherence (WCC) and Social Inference theory. Fourteen young adults with AS and 24 age-matched controls were assessed on cognitive tasks measuring WCC processes, social inference or Theory of Mind ability, and the ability to interpret ironic remarks. Results indicated that the ability to understand the belief states of others is critical to understanding ironic language in AS.

Clinical Insights into Pragmatic Theory: Frontal Lobe Deficits and Sarcasm

The validity of psycholinguistic theories of sarcasm was explored by examining subjects with mainly frontal lobe (FL) damage and concomitant concreteness of thought. The majority of FL subjects could interpret consistent verbal exchanges but not literally contradictory (sarcastic) verbal exchanges which implied that the literal meaning of a sarcastic comment needs to be rejected in order for the inference to be detected. Subsidiary analyses confirmed that failure on sarcasm tasks was associated with poor conceptual skills. Ability to process attitude was not associated with success at recognizing sarcasm. This suggested that attitude is not pivotal to the detection of sarcastic inference.

Pragmatic Language Skills after Closed Head Injury: Ability to Meet the Informational Needs of the Listener

Two closed-head-injured subjects and 12 non-brain-damaged controls explained a novel procedure to a blindfolded third person. Their productions were transcribed and scored by nine judges on ratings scales based on Grices maxims of quantity and manner. The two closed-head injury (CHI) productions were significantly inferior to the controls, both being rated as disorganized, confusing, and ineffective. While one subjects production was considered overly repetitive, the other had too little detail. In order to specify, more exactly, the nature of the deficits, a cohesion analysis and an analysis of informational content were performed. The cohesion analysis suggested that the CHI productions were generally similar to the controls. The informational analysis was more revealing. Judgements of detail and repetitiveness were reflected in the number of new and repeated propositions. Errors in sequencing and inclusion of irrelevant propositions contributed to the disorganized and confusing nature of the texts. The results were interpreted within the framework of frontal lobe deficits in monitoring and regulation of performance.

Recognition of emotion from facial expression following traumatic brain injury

Primary Objective: To assess three domains of emotion recognition in people with traumatic brain injury (TBI). Research design: A between group comparison. Procedures: Twenty-four participants with severe TBI and 15 matched participants without brain damage were asked to label and match facial expressions with and without context. The participants with TBI were also interviewed regarding changes in subjective experience of emotion. Main outcomes and results: Participants with TBI were found to be significantly impaired on expression labelling and matching, but experienced some improvement when provided with context. Negative emotions were particularly affected. Affective semantic knowledge and face perception appeared to be relatively intact in this group. The majority of participants with TBI reported some change in the post-injury experience of everyday emotion, although the pattern of changes differed greatly between individuals. Reduced subjective experience, especially of sadness and fear, was associated with poor emotion matching but not emotion labelling.

Incidence of hospital-treated traumatic brain injury in an Australian community

This paper reports findings from an incidence study of head trauma in a defined population. In the North Coast Health Region of NSW, 1,259 subjects with head trauma were admitted to hospitals in a 12‐month period in 1988. Direct examination of the medical records confirmed brain injury in only 413 of these cases, corresponding to an annual incidence of approximately 100/100,000 resident population. Although most injuries (62.2%) were mild, 38% were serious (either moderate, 20.3%, or severe, 13.6%; and 3.9% died after admission to hospital). Severe brain injury represented an annual incidence of 12/100,000 resident population. Road traffic accidents accounted for a higher proportion of injuries in the severe group in comparison with the other injury groups. Methodological issues involved in case ascertainment of brain injury are discussed.