Informed consent is key to ethical clinical research and treatment, but partially rests on the ability of individual patients or research participants to use disclosed information to make a meaningful choice. Although the construct of decisional capacity emerged from legal and philosophical traditions, several investigators have begun examining the relationship of specific neuropsychological abilities to decisional capacity. This line of research may foster development of better consent procedures, as well as aid in refining the construct of decisional capacity toward a form that better reflects the underlying neurocognitive processes. We conducted a systematic search of the published literature and thereby identified and reviewed 16 published reports of empirical studies that examined the relationship between specific neuropsychological abilities and capacity to consent to research or treatment. Significant relationships between neuropsychological scores and decisional capacity were present across all the reviewed studies. The degree to which specific neuropsychological abilities have particular relevance to decisional capacity remains uncertain, but the existing studies provide a solid basis for a priori hypotheses for future investigations. These ongoing efforts represent an important conceptual and empirical bridge between bioethical, legal, and neuropsychological approaches to understanding meaningful decision-making processes. (JINS, 2007, 13, 1047–1059.)

There has been increasing interest in the semantic cognitive system in schizophrenia. Recent findings suggest a possible breakdown of semantic information processing in this disorder. The current study attempts to further examine semantic organization in schizophrenia. Twenty-eight chronic, early-onset schizophrenic patients and 32 controls were matched for prcmorbid intelligence and compared in their ability to spontaneously cluster exemplars from a specific category during a fluency task. Using multidimensional scaling and clustering techniques, 11 exemplars occurring most frequently in both groups were chosen for examination of their relative “proximity” during word generation. Patients with schizophrenia showed a less stable two-dimensional organization of exemplars and were less likely to group exemplars into subordinate clusters than were normals. These results suggest that semantic networks arc disorganized in these patients. These findings may have some implications for the debate over the origin of “thought disorder” in schizophrenia. (JINS, 1996, 2, 267–273.)

Subjective memory complaints (SMCs) are part of the diagnostic criteria for Mild Cognitive Impairment (MCI), yet little is known about their etiology. In some previous studies, no direct relation has been found between SMCs and objective memory performance, yet significant correlations have been identified between SMCs and psychological factors such as depression and anxiety. In the current study, we examined whether negative affect moderated the relation between objective memory functioning and SMCs in a sample of healthy, non-demented participants aged 65 and older. As predicted, several negative affect measures moderated the relationship between objective cognitive functioning and SMCs. In the absence of objective memory impairment as indexed by the Rey Auditory Verbal Learning Test (RAVLT) and the Dementia Rating Scale-2nd Edition (DRS-2), higher levels of negative affect were associated with increased levels of SMCs. Moreover, a lower order negative affect factor, anxiety sensitivity, significantly moderated the relation between objective memory functioning and SMCs, after controlling for higher order measures of general negative affectivity. Findings suggest that negative affect, particularly anxiety sensitivity, distorts the subjective appraisal of one's own memory, such that people high on negative affect factors report more episodes of forgetting, even in the absence of objective cognitive impairments. (JINS, 2008, 14, 327–336.)

Demographically adjusted norms generally enhance accuracy of inferences based on neuropsychological assessment. However, we hypothesized that demographic corrections diminish predictive accuracy for real-world activities with absolute cognitive demands. Driving ability was assessed with a 45-minute drive along a standardized on-road route in participants aged 65+ (24 healthy elderly, 26 probable Alzheimer’s disease, 33 Parkinson’s disease). Neuropsychological measures included: Trail-Making A and B, Complex Figure, Benton Visual Retention, and Block Design tests. A multiple regression model with raw neuropsychological scores was significantly predictive of driving errors (R2 = .199, p = .005); a model with demographically adjusted scores was not (R2 = .113, p = .107). Raw scores were more highly correlated with driving errors than were adjusted scores for each neuropsychological measure, and among healthy elderly and Parkinson’s patients. When predicting real-world activities that depend on absolute levels of cognitive abilities regardless of demographic considerations, predictive accuracy is diminished by demographic corrections. (JINS, 2010, 16, 679–686.)

The relationship of psychological and cognitive factors in the development of the postconcussion syndrome (PCS) following mild uncomplicated traumatic brain injury (mTBI) has received little study. This may be because of the widely held belief that neurological factors are the cause of early PCS symptoms, whereas psychological factors are responsible for enduring symptoms. To further understand these relationships, the association between PCS and neuropsychological and psychological outcome was investigated in 122 general trauma patients, many of whom had orthopedic injuries, around 5 days following mTBI. Apart from verbal fluency, participants with a PCS did not differ in their performances on neuropsychological measures compared to those without a PCS. Individuals with a PCS reported significantly more psychological symptoms. Large effect sizes present on the psychological measures showed that the difference between participants with a PCS and without was greater on psychological than on neuropsychological measures. Analyses also revealed a relationship between opioid analgesia and depression, anxiety and stress, and opioids and reduced learning. The results suggest that psychological factors are present much earlier than has previously been considered in the development of the PCS. (JINS, 2006, 12, 792–801.)

Objectives: With comparable baseline performance on executive functions (EF) and memory between Alzheimer’s disease (AD) and behavioral-variant frontotemporal dementia (bvFTD), it is currently unclear if both diseases can be distinguished longitudinally on these measures reliably. Methods: A total of 111 participants (33 AD, 31 bvFTD, and 47 controls) were followed-up annually over a 4-year period and tested on measures of EF, memory, and orientation. Linear mixed-effect models were constructed using disease severity as a nuisance variable to examine profiles of neuropsychological performance decline. Results: At baseline, overlap in terms of cognitive impairment between bvFTD and AD on multiple EF, memory, and orientation measures was present. Longitudinally, only disinhibition (Hayling total errors) appeared sensitive to discriminating AD from bvFTD; however, only after the first annual follow-up. Subgroup analyses on smaller samples revealed comparable profiles on EF tasks at baseline and over time between bvFTD and AD who presented with impaired EF at presentation, and on memory and orientation tasks between AD and bvFTD who presented with severe amnesia. Conclusions: Our results replicate previous findings showing only moderate discriminability between AD and bvFTD at clinical presentation on EF and memory measures. More importantly, we also show that longitudinal trajectories strongly overlap for both dementias on these measures. Disinhibition emerged as the sole measure that in the long run was significantly more impaired in bvFTD. Future studies should use tests designed to target cortical regions that are specifically impaired in bvFTD, such as the ventromedial prefrontal cortex, to improve the accurate discrimination of these diseases. (JINS, 2017, 23, 34–43)

This study evaluated cognitive set-shifting in 12 patients with focal lesions in the lateral prefrontal cortex (LPC) by examining their performance on the Trail Making Test from the Delis-Kaplan Executive Function System (D-KEFS). Patients with LPC lesions performed significantly worse than controls on the D-KEFS Trail Making Test on the Letter Sequencing, Number-Letter Switching (set-shifting), and Motor Speed conditions. Patients with LPC lesions performed significantly more slowly on the Number-Letter Switching condition even after controlling for performance on the four baseline conditions of the test. In addition, patients with LPC lesions exhibited significantly elevated error rates on the Number-Letter Switching condition. Results suggest that LPC lesions can lead to impaired cognitive set-shifting on a visual-motor sequencing task. (JINS, 2007, 13, 704–709.)

Patients with dementia of the Alzheimer's type (DAT) and their matched controls wrote, on a computer graphics tablet, 4 consecutive, cursive letter ‘l’s, with varying levels of visual feedback: noninking pen and blank paper so that only the hand movements could be seen, noninking pen and lined paper to constrain their writing, goggles to occlude the lower visual field and eliminate all relevant visual feedback, and inking pen with full vision. The kinematic measures of stroke length, duration, and peak velocity were expressed in terms of consistency via a signal-to-noise ratio (M value of each parameter divided by its SD). Irrespective of medication or severity, DAT patients had writing strokes of significantly less consistent lengths than controls', and were disproportionately impaired by reduced visual feedback. Again irrespective of medication or severity, patients' strokes were of significantly less consistent duration, and significantly less consistent peak velocity than controls', independent of feedback conditions. Patients, unlike controls, frequently perseverated, producing more than 4 ‘l’s, or multiple sets of responses, which was not differentially affected by level of visual feedback. The more variable performance of patients supports a degradation of the base motor program, and resembles that of Huntington's rather than Parkinson's disease patients. It may indeed reflect frontal rather than basal ganglia dysfunction. (JINS, 1999, 5, 20–25.)

Older adults with early forms of neurodegenerative disease are at risk for functional disability, which is often defined by the loss of independence in instrumental activities of daily living (IADLs). The current study investigated the influence of mild changes in everyday functional abilities (referred to as functional limitations) on risk for development of incident functional disability. A total of 407 participants, who were considered cognitively normal or diagnosed with mild cognitive impairment (MCI) at baseline, were followed longitudinally over an average 4.1 years (range=0.8–9.2 years). Informant-based ratings from the Everyday Cognition (ECog; Farias et al., 2008) and the Instrumental Activities of Daily Living (Lawton & Brody, 1969) scales assessed the degree of functional limitations and incident IADL disability, respectively. Cox proportional hazards models revealed that more severe functional limitations (as measured by the Total ECog score) at baseline were associated with approximately a four-fold increased risk of developing IADL disability a few years later. Among the ECog domains, functional limitations in Everyday Planning, Everyday Memory, and Everyday Visuospatial domains were associated with the greatest risk of incident functional disability. These results remained robust even after controlling for participants’ neuropsychological functioning on tests of executive functions and episodic memory. Current findings indicate that early functional limitations have prognostic value in identifying older adults at risk for developing functional disability. Findings highlight the importance of developing interventions to support everyday abilities related to memory, executive function, and visuospatial skills in an effort to delay loss of independence in IADLs. (JINS, 2015, 21, 688–698)

Patients with apraxia are more impaired when performing transitive pantomimes than intransitive gestures. This dissociation might be related to the differences in movement complexity. Alternatively, the programs for intransitive gestures might be better defined, more widely distributed, or easier to activate than are those for transitive pantomimes. The purpose of this study was to test the complexity versus representational hypotheses. Twenty right-handed normal subjects both performed and discriminated correct from incorrect transitive pantomimes and intransitive gestures. The discrimination was performed by having subjects point at illustrations of hand postures. The subjects performed better when discriminating postures than when performing gestures or pantomimes. On both the production and discrimination tests, subjects performed better with intransitive gestures than transitive pantomimes. Although the finding that even normal subjects had more difficulty performing transitive pantomimes than intransitive gestures might appear to support the complexity hypothesis, that subjects also had more difficulty discriminating transitive than intransitive postures supports the representational activation hypothesis. (JINS, 2002, 8, 958–963.)

Verbal learning and memory (VLM) following pediatric stroke was characterized in a cross-sectional neuropsychological and neuroimaging study of 26 subjects, aged 5 to 17, with a history of pediatric stroke and 26 age, SES, and gender matched orthopedic controls. Further comparisons were made between the VLM profiles of stroke subjects with right versus left hemisphere lesions and early (≤12 months) versus late (>12 months) strokes. Overall, stroke subjects scored significantly lower than control subjects on several VLM indices (California Verbal Learning Test–Children; CVLT–C), as well as on measures of intellectual functioning (IQ) and auditory attention/working memory (Digit Span). Subgroup analyses of the stroke population found no significant differences in VLM, Digit Span, Verbal IQ or Performance IQ when left-hemisphere lesion subjects were compared to right-hemisphere lesion subjects. In contrast, early strokes were associated with significantly fewer words recalled after delay, reduced discriminability (fewer correct hits relative to false positive errors on recognition testing), and relatively worse auditory attention/working memory scores (Digit Span). These findings indicate that pediatric stroke subjects demonstrated more VLM impairment than control subjects, and early strokes were associated with greater recall and recognition deficits. In stark contrast with adult-onset stroke, both left- and right-hemisphere lesions during childhood resulted in similar VLM performance. (JINS, 2004, 10, 742–752.)

Many individuals who sustain moderate–severe traumatic brain injuries (TBI) are poor at recognizing emotional expressions, with a greater impairment in recognizing negative (e.g., fear, disgust, sadness, and anger) than positive emotions (e.g., happiness and surprise). It has been questioned whether this “valence effect” might be an artifact of the wide use of static facial emotion stimuli (usually full-blown expressions) which differ in difficulty rather than a real consequence of brain impairment. This study aimed to investigate the valence effect in TBI, while examining emotion recognition across different intensities (low, medium, and high).

Method: Twenty-seven individuals with TBI and 28 matched control participants were tested on the Emotion Recognition Task (ERT). The TBI group was more impaired in overall emotion recognition, and less accurate recognizing negative emotions. However, examining the performance across the different intensities indicated that this difference was driven by some emotions (e.g., happiness) being much easier to recognize than others (e.g., fear and surprise). Our findings indicate that individuals with TBI have an overall deficit in facial emotion recognition, and that both people with TBI and control participants found some emotions more difficult than others. These results suggest that conventional measures of facial affect recognition that do not examine variance in the difficulty of emotions may produce erroneous conclusions about differential impairment. They also cast doubt on the notion that dissociable neural pathways underlie the recognition of positive and negative emotions, which are differentially affected by TBI and potentially other neurological or psychiatric disorders. (JINS, 2014, 20, 1–10)

Background: Agenesis of the corpus callosum (AgCC) involves congenital absence of all or part of the corpus callosum. Because the disorder can only be firmly diagnosed via neuroradiology, it has a short research history, and only recently has the cognitive syndrome become clear. Purpose: Our purpose is to review the primary deficits in AgCC that constitute the core syndrome. Conclusions: The cores syndrome includes: (1) reduced interhemispheric transfer of sensory-motor information; (2) reduced cognitive processing speed; and (3) deficits in complex reasoning and novel problem-solving. These domains do not appear to reflect different neuroanatomical abnormalities, but rather different domains of expression of reduced interhemispheric communication from callosal absence. Implications: These core deficits are expressed across various domains of cognitive, behavioral, and social functioning. The impact of these deficits varies across development and may be moderated by individual factors such as co-occurrence of other neurodevelopmental conditions, general intellectual capacity, and environmental support. (JINS, 2019, 25, 324–330)

This review explores the relationships between depression, apathy, and anosognosia in Alzheimer's disease. Depressed mood is found to be associated with less anosognosia, while greater apathy is associated with more anosognosia, and the contrasting reasons for these associations are discussed. The review also describes recent research findings indicating a dissociation between impaired awareness of condition/deficit and preserved emotional reactivity in response to illness-related material or the experience of failure in tests. We conclude by pointing to future directions for this area of research and clinical implications. (JINS, 2014, 20, 2–7)

The Clock Drawing Test (CDT) is widely used in the assessment of dementia and is known to be sensitive to the detection of deficits in neurodegenerative disorders such as Alzheimer's disease (AD). CDT performance is dependent not only on visuospatial and constructional abilities, but also on conceptual and executive functioning; therefore, it is likely to be mediated by multiple brain regions. The purpose of the present study was to identify component cognitive processes and regional cortical volumes that contribute to CDT performance in AD. In 29 patients with probable AD, CDT performance was significantly related to right-, but not left-hemisphere, regional gray matter volume. Specifically, CDT score correlated significantly with the right anterior and posterior superior temporal lobe volumes. CDT scores showed significant relationships with tests of semantic knowledge, executive function, and visuoconstruction, and receptive language. These results suggest that in AD patients, CDT performance is attributable to impairment in multiple cognitive domains but is related specifically to regional volume loss of right temporal cortex. (JINS, 1999, 5, 502–509.)

Deficits in multiple sclerosis (MS) patients’ performance on the Stroop Test have been attributed to problems with processing speed and selective attention. Data for 248 MS patients and 178 controls on all three trials of the Stroop were combined using various scoring formulas proposed for assessing processing speed, color difficulty, and interference. The greatest differences between patients and controls involved processing speed. Formulas purporting to measure interference yielded highly inconsistent results: Significant differences between groups were found on two of the most common measures but were in opposite directions. This contradiction stems from the failure of both measures to effectively control for processing speed when assessing interference. Three alternative measures, using relative, ratio, and residualized scores, offer much better indices of interference. When assessed with these alternative measures, interference increased with age, but no differences between patients and controls were found. Difficulties that MS patients have with the Stroop Test are confined to processing speed. (JINS, 2009, 15, 451–458.)

Objectives: Behavioral variant frontotemporal dementia (bvFTD) is characterized by early atrophy in the frontotemporoinsular regions. These regions overlap with networks that are engaged in social cognition-executive functions, two hallmarks deficits of bvFTD. We examine (i) whether Network Centrality (a graph theory metric that measures how important a node is in a brain network) in the frontotemporoinsular network is disrupted in bvFTD, and (ii) the level of involvement of this network in social-executive performance. Methods: Patients with probable bvFTD, healthy controls, and frontoinsular stroke patients underwent functional MRI resting-state recordings and completed social-executive behavioral measures. Results: Relative to the controls and the stroke group, the bvFTD patients presented decreased Network Centrality. In addition, this measure was associated with social cognition and executive functions. To test the specificity of these results for the Network Centrality of the frontotemporoinsular network, we assessed the main areas from six resting-state networks. No group differences or behavioral associations were found in these networks. Finally, Network Centrality and behavior distinguished bvFTD patients from the other groups with a high classification rate. Conclusions: bvFTD selectively affects Network Centrality in the frontotemporoinsular network, which is associated with high-level social and executive profile. (JINS, 2016, 22, 250–262)

The NIH Toolbox (NIHTB) Pattern Comparison Processing Speed Test was developed to assess processing speed within the NIHTB for the Assessment of Neurological Behavior and Function Cognition Battery (NIHTB-CB). This study highlights validation data collected in adults ages 18–85 on this measure and reports descriptive data, test–retest reliability, construct validity, and preliminary work creating a composite index of processing speed. Results indicated good test–retest reliability. There was also evidence for both convergent and discriminant validity; the Pattern Comparison Processing Speed Test demonstrated moderate significant correlations with other processing speed tests (i.e., WAIS-IV Coding, Symbol Search and Processing Speed Index), small significant correlations with measures of working memory (i.e., WAIS-IV Letter-Number Sequencing and PASAT), and non-significant correlations with a test of vocabulary comprehension (i.e., PPVT-IV). Finally, analyses comparing and combining scores on the NIHTB Pattern Comparison Processing Speed Test with other measures of simple reaction time from the NIHTB-CB indicated that a Processing Speed Composite score performed better than any test examined in isolation. The NIHTB Pattern Comparison Processing Speed Test exhibits several strengths: it is appropriate for use across the lifespan (ages, 3–85 years), it is short and easy to administer, and it has high construct validity. (JINS, 2014, 20, 1–12)

Mild traumatic brain injury (mTBI) affects a significant number of combat veterans returning from Operation Enduring Freedom/Operation Iraqi Freedom (OEF/OIF). Although resolution of mTBI symptoms is expected over time, some individuals continue to report lingering cognitive difficulties. This study examined the contributions of self-reported mTBI injury characteristics (e.g., loss of consciousness, post-traumatic amnesia) and psychiatric symptoms to both subjective and objective cognitive functioning in a sample of 167 OEF/OIF veterans seen in a TBI clinic. Injury characteristics were not associated with performance on neuropsychological tests but were variably related to subjective ratings of cognitive functioning. Psychiatric symptoms were highly prevalent and fully mediated most of the relationships between injury characteristics and cognitive ratings. This indicates that mTBI characteristics such as longer time since injury and loss of consciousness or post-traumatic amnesia can lead to increased perceived cognitive deficits despite having no objective effects on cognitive performance. Psychiatric symptoms were associated with both cognitive ratings and neuropsychological performance, illustrating the important role that psychiatric treatment can potentially play in optimizing functioning. Finally, subjective cognitive ratings were not predictive of neuropsychological performance once psychiatric functioning was statistically controlled, suggesting that neuropsychological assessment provides valuable information that cannot be gleaned from self-report alone. (JINS, 2012, 18, 576–584)

Long-term memory (LTM) is one of the diverse cognitive functions adversely affected by multiple sclerosis (MS). The LTM deficits have often been attributed to failure of retrieval, whereas encoding processes are presumed intact. However, support for this view comes primarily from studies in which encoding and retrieval operations were not investigated systematically. In the current study, we used an encoding specificity paradigm to examine the robustness of encoding in MS and to specifically evaluate the impact of the disease on contextual memory. We hypothesized that persons with MS would exhibit a selective impairment in retrieving items from LTM when required to generate new cue-target associations at encoding, but not when cues held a strong preexisting relationship to the targets. The findings supported the hypotheses. We conclude that the mnemonic deficits associated with MS affect both encoding and retrieval. Specifically, problems with binding of contextual information at encoding impair effective retrieval of memories. Nonetheless, access to these memories can be gained through preexisting associations organized in the semantic network. (JINS, 2002, 8, 395–409.)