Face memory impairments in patients with frontal lobe damage.

OBJECTIVE: To determine whether damage to prefrontal cortex is associated with face memory impairment. BACKGROUND: Neurophysiologic and functional imaging studies suggest that prefrontal cortex is a key component of a distributed neural network that mediates face recognition memory. However, there have been few attempts to examine the impact of frontal lobe damage on face memory performance. METHODS: Patients with focal frontal lobe lesions and normal control subjects were administered two-alternative forced-choice and single-probe "yes/no" tests of recognition memory for novel faces. Retrograde memory was assessed by using famous faces as stimuli. RESULTS: Compared with control subjects, patients with frontal lobe lesions showed evidence of marked anterograde and relatively mild retrograde face memory impairment. In addition, patients with right frontal lesions demonstrated increased susceptibility to false recognition, consistent with the breakdown of strategic memory retrieval, monitoring, and decision functions. CONCLUSIONS: Prefrontal cortex plays an important role in the executive control of face memory encoding and retrieval. Left and right prefrontal regions seem to make different contributions to recognition memory performance.

Valence-dependent modulation of psychophysiological measures: is there consistency across repeated testing?

The present study used the picture perception paradigm to examine the extent to which three well-documented psychophysiological measures demonstrate consistency across time in response to emotional stimuli. The three measures were the eye-blink startle response and the activation in two facial muscle regions (zygomatic and corrugator). Twenty-seven young women were assessed on two occasions, 2 weeks apart. Whereas activation in the corrugator and zygomatic muscle regions demonstrated the predicted patterns at both assessments (with some attenuation in the zygomatic muscle regions), the startle response had limited consistency across the two assessments. The startle response revealed the predicted linear pattern of valence modulation during the first assessment. During the second assessment, startle magnitude response was a quadratic function of valence ratings and a linear function of arousal ratings. The unexpected pattern of startle response during the second session appeared to be related to the content of the pleasant slides, with action slides generating quadratic valence modulation and erotic slides continuing to exhibit the expected linear valence modulation.

Pervasive emotion recognition deficit common to alexithymia and the repressive coping style.

OBJECTIVE: Previous research has demonstrated a deficit in the ability to recognize emotions in alexithymic individuals. The repressive coping style is thought to preferentially impair the detection of unpleasant compared with pleasant emotions, and the degree of deficit is typically thought to be less severe than in alexithymia. We compared emotion recognition ability in both individuals with alexithymia and those with the repressive coping style. METHODS: Three hundred seventy-nine subjects completed the 20-item Toronto Alexithymia Scale, the Levels of Emotional Awareness Scale, the Marlowe-Crowne Scale (a measure of repressive defensiveness), the Bendig Short Form of the Taylor Manifest Anxiety Scale, and the Perception of Affect Task. The Perception of Affect Task consists of four 35-item emotion recognition subtasks: matching sentences and words, faces and words, sentences and faces, and faces and photographs of scenes. The stimuli in each subtask consist of seven emotions (happiness, sadness, anger, fear, disgust, surprise, and neutral) depicted five times each. Recognition accuracy results were collapsed across subtasks within each emotion category. RESULTS: Highly alexithymic subjects (for all, p<.01) and those with low emotional awareness (for all, p<.001) were consistently less accurate in emotion recognition in all seven categories. Highly defensive subjects (including repressors) were less accurate in the detection of anger, sadness, fear, and happiness (for all, p<.05). Furthermore, scores on the Levels of Emotional Awareness Scale accounted for significantly more variance in performance on the Perception of Affect Task than scores on the Marlowe-Crowne Scale (p<.01). CONCLUSIONS: The results indicate that alexithymia and the repressive coping style are each associated with impairments in the recognition of both pleasant and unpleasant emotions and that the two styles of emotional self-regulation differ more in the magnitude than in the quality of these impairments.

Executive control functions in degenerative dementias: a comparative review.

This paper reviews the literature concerning executive control impairments in degenerative dementias. The construct of executive control functioning is examined, as is the neuroanatomy of frontal-subcortical networks, believed to underlie executive function (EF) impairments. The pattern of EF impairments in Alzheimer's disease (AD) which affects temporal and parietal brain regions most severely is contrasted with observed executive dysfunctions in patients with dementias involving degeneration of primarily frontal and frontal-subcortical brain areas. EF impairments are present in each of these types of dementing illnesses. Although EF impairments are present in AD, they are less prominent than the memory disorder in the neuropsychological profile of the disease and tend to become more pronounced later in the course of the illness. In contrast, patients with frontal or frontal-subcortical dementia may demonstrate executive dysfunction, which occurs earlier in the disease progression and may be initially more severe.

Early detection of probable idiopathic Parkinson's disease: I. Development of a diagnostic test battery.

We developed a test battery as an inexpensive and objective aid for the early diagnosis of idiopathic Parkinson's disease (iPD) and its differential diagnoses. The test battery incorporates tests of motor function, olfaction, and mood. In the motor task, a wrist flexion-and-extension task to different targets, movement velocities were recorded. Olfaction was tested with the University of Pennsylvania Smell Identification Test. Mood was assessed with the Beck Depression Inventory. An initial regression model was developed from the results of 19 normal control subjects and 18 patients with early, mild, probable iPD. Prospective application to an independent validation set of 122 normal control subjects and 103 patients resulted in an 88% specificity rate and 69% sensitivity rate, with an area under the Receiver Operator Characteristic curve of 0.87.

Fear recognition deficits after focal brain damage: a cautionary note.

OBJECTIVE: To test the hypothesis that fear recognition deficits in neurologic patients reflect damage to an emotion-specific neural network. BACKGROUND: Previous studies have suggested that the perception of fear in facial expressions is mediated by a specialized neural system that includes the amygdala and certain posterior right-hemisphere cortical regions. However, the neuropsychological findings in patients with amygdala damage are inconclusive, and the contribution of distinct cortical regions to fear perception has only been examined in one study. METHODS: We studied the recognition of six basic facial expressions by asking subjects to match these emotions with the appropriate verbal labels. RESULTS: Both normal control subjects (n = 80) and patients with focal brain damage (n = 63) performed significantly worse in recognizing fear than in recognizing any other facial emotion, with errors consisting primarily of mistaking fear for surprise. Although patients were impaired relative to control subjects in recognizing fear, we could not obtain convincing evidence that left, right, or bilateral lesions were associated with disproportionate impairments of fear perception once we adjusted for differences in overall recognition performance for the other five facial emotion categories. The proposed special role of the amygdala and posterior right-hemisphere cortical regions in fear perception was also not supported. CONCLUSIONS: Fear recognition deficits in neurologic patients may be attributable to task difficulty factors rather than damage to putative neural systems dedicated to fear perception.

An event-related potential examination of masked and unmasked repetition priming in Alzheimer's disease: implications for theories of implicit memory.

Fifteen patients diagnosed with Alzheimer's disease (AD) and 26 matched older controls engaged in a lexical-decision task with a list of words and nonwords while event-related brain potentials (ERPs) were recorded. Two repetition conditions were embedded in the list: words repeated at relatively long lags or words repeated shortly after a brief masked presentation. Although older controls displayed behavioral and ERP repetition priming for words repeated at long lags, consistent with previous studies, AD patients displayed neither. In contrast, both controls and AD patients displayed an ERP repetition priming effect for words repeated shortly after a brief masked presentation. ERP priming effects for masked and unmasked repetition differed in older controls, and additionally, the ERP masked priming effect differed between controls and AD patients. Results are discussed in the context of studies that have examined memory performance in brain-damaged populations using an impaired-intact dichotomy.

Dissociation between verbal and autonomic measures of memory following frontal lobe damage.

OBJECTIVE: The objective of this study was to contrast overt verbal versus covert autonomic responses to facial stimuli in a patient with false recognition following frontal lobe damage. BACKGROUND: False recognition has been linked to frontal lobe dysfunction. However, previous studies have relied exclusively on overt measures of memory and have not examined whether or not patients with false recognition continue to demonstrate preserved covert discrimination of familiar and unfamiliar items. METHODS: We recorded skin conductance responses (SCRs) in a patient with frontal lobe damage and in normal control subjects while they performed a familiarity decision task using famous and unfamiliar faces as stimuli. RESULTS: Patient J.S. produced significantly more overt false recognition errors and misidentifications in response to unfamiliar faces than control subjects. However, similar to the control subjects, he showed accurate covert autonomic discrimination of truly familiar faces from unfamiliar ones. Furthermore, SCRs to falsely recognized unfamiliar faces were not significantly different from SCRs generated to unfamiliar faces that J.S. correctly rejected. CONCLUSIONS: Our findings provide further neuropsychological evidence that overt and covert forms of face recognition memory are dissociable. In addition, the failure to detect an autonomic correlate for the false recognition errors and misidentifications in J.S. suggests that these memory distortions were not related to the spurious activation of stored memory representations for specific familiar faces. Instead, these incorrect responses may have been driven by the sense of familiarity evoked by novel faces that had a general resemblance to faces encountered previously. We propose that false recognition in J.S. resulted from the breakdown of strategic frontal memory retrieval, monitoring, and decision functions critical for attributing the experience of familiarity to its appropriate source.

Measures of deficit unawareness for predicted performance experiments.

Predicted performance experiments attempt to quantify an impaired individual's awareness of his or her deficit. These experiments measure perceived ability by the individual's prediction of his or her performance on a specific cognitive task and actual ability by his or her subsequent performance on that task. To date, the most comprehensive predicted performance experiment is the one proposed and implemented by McGlynn and Kaszniak (1991b). This experiment is potentially capable of removing a number of influences that may be confounded with deficit unawareness; however, it is not obvious what method of quantitative analysis best exploits this capability. In the present report, several possibilities are discussed. The limitations of McGlynn and Kaszniak's method are identified, and a more satisfying measure of deficit unawareness is proposed.

Impaired verbal and nonverbal emotion recognition in alexithymia.

Although clinical observations suggest that alexithymic individuals have a deficit in their ability to recognize emotional stimuli and that this deficit is not simply due to a problem in verbal labeling, these two hypotheses have not been empirically confirmed. Three hundred eighty participants in a community survey without current or past histories of psychiatric disorder completed two independent measures of alexithymia [the Levels of Emotional Awareness Scale (LEAS) and the Toronto Alexithymia Scale (TAS-20)] and the Perception of Affect Task (PAT), a 140-item measure of the ability to match emotion stimuli. The PAT includes four subtasks that require the subject to match verbal or nonverbal emotion stimuli with verbal or nonverbal emotion responses. The subtasks include matching sentences and words (verbal-verbal), faces and words (nonverbal-verbal), sentences and faces (verbal-nonverbal), and faces and photographs of scenes (nonverbal-nonverbal). Across the entire sample, higher (alexithymic) TAS-20 and lower LEAS scores were both correlated with lower accuracy rates on each of the subtasks of the PAT (p < .001), accounting for 10.5% and 18.4% of the variance, respectively. Fifty-one subjects met TAS-20 criteria for alexithymia. Alexithymic individuals scored lower than other subjects on purely nonverbal matching, purely verbal matching, and mixed verbal-nonverbal matching (all p < .001). These results suggest that alexithymia is associated with impaired verbal and nonverbal recognition of emotion stimuli and that the hallmark of alexithymia, a difficulty in putting emotion into words, may be a marker of a more general impairment in the capacity for emotion information processing.

Trait shyness in the elderly: evidence for an association with Parkinson's disease in family members and biochemical correlates.

The emergence of potential treatments to slow the progression of idiopathic Parkinson's disease (PD) has increased the need for early identification of persons at risk. Although considered controversial, some prior studies indicate that PD patients may have premorbid histories of greater trait introversion or shyness as well as increased rates of disorders associated with shyness (e.g., anxiety, affective disorders, and irritable bowel syndrome). Essential features of trait shyness include (a) inhibited and avoidant behaviors and (b) physiological hyperreactivity to the novel or unfamiliar. In parallel, (a) depression in PD patients is associated with increased harm avoidance (a possible serotonergic function), and (b) PD patients have premorbid and comorbid decreases in novelty-seeking (a possible dopaminergic function). Taken together, previous research suggests the following hypotheses: (1) given evidence for marked heritability of shyness, shy elderly should report higher rates of PD in their family members than would nonshy elderly; and (2) shy elderly without PD should exhibit psychological and biologic characteristics similar to those reported in PD. Two groups, representing the top 27% (n = 37) and bottom 31% (n = 43) of scores on a standardized shyness scale, were drawn from a larger cohort of 138 older adults (ages 50-90) living in an active retirement community. Seventeen percent of the shy versus 2% of the nonshy reported PD in a family member or self (P < .05). Shy elderly were significantly more anxious (P < .01) and depressed (P < .05) than were the nonshy.(ABSTRACT TRUNCATED AT 250 WORDS)

Psychological characteristics and subjective intolerance for xenobiotic agents of normal young adults with trait shyness and defensiveness. A parkinsonian-like personality type?

The present study examines the psychological characteristics and self-reported responses to xenobiotic agents such as tobacco smoke and pesticide of normal young adults with personality traits similar to those claimed for Parkinsonian patients. Previous research, though controversial, has suggested that persons with idiopathic Parkinson's disease (PD) have premorbid personality traits that may include shyness and repressive defensiveness. Other epidemiological evidence indicates that PD patients may have premorbidly increased prevalence of anxiety, affective, and/or somatoform disorders; decreased rates of smoking and alcohol consumption; and elevated exposure to herbicides or pesticides. A total of 783 college students enrolled in an introductory psychology course completed the Cheek-Buss Scale (shyness), the Marlowe-Crowne Social Desirability Scale (defensiveness), Symptom Checklist 90 (revised), the Mastery Scale, a health history checklist, and rating scales for frequency of illness from alcohol and 10 common environmental chemicals. Subjects were divided into four groups on the basis of above- versus below-median scores on the Cheek-Buss and Marlowe-Crowne scales (persons high in shyness and defensiveness, those high only in shyness, those high only in defensiveness, and those low in both shyness and defensiveness). The group high in shyness but low in defensiveness had the highest, whereas the group low in shyness but high in defensiveness had the lowest, total scores on the SCL-90-R; the two shyest groups were lowest in sense of mastery.(ABSTRACT TRUNCATED AT 250 WORDS)

Source memory: extending the boundaries of age-related deficits.

Previous research has established that elderly adults can exhibit impaired memory for the source of newly acquired facts even when levels of fact recall in old and young do not differ. However, source memory impairments have been observed only under conditions of many-to-1 mapping: A large number of facts are related to either of 2 sources. It is thus possible that apparent source memory impairments reflect a more general age-related problem in handling many-to-1 mappings. Two experiments provide evidence against this possibility by demonstrating age-related source memory deficits with 1-to-1 mapping between facts and sources. The data also indicate that source memory deficits are observed across encoding tasks that manipulate the allocation of attention to the source or to the fact.

Memory impairment and executive control in individuals with stroke-induced aphasia.

The purpose of this study was to examine memory abilities of aphasic individuals in relation to site of neurological lesion. Fourteen individuals with stroke-induced aphasia (7 with anterior lesions; 7 with posterior lesions) and 14 demographically matched control subjects were given selected tests of short-term memory (STM) and long-term memory (LTM). Stroke patients were impaired relative to control subjects on tests of verbal memory, with greater impairment of LTM associated with anterior lesions and greater impairment of STM associated with posterior lesions. Verbal memory performance did not correlate highly with language ability, and did not appear to be simply a consequence of language impairment. Executive control deficits were postulated as explanatory of the LTM impairment associated with anterior lesions.

Clinical trial of indomethacin in Alzheimer's disease.

In a 6-month, double-blind, placebo-controlled study, 100 to 150 mg/d indomethacin appeared to protect mild to moderately impaired Alzheimer's disease patients from the degree of cognitive decline exhibited by a well-matched, placebo-treated group. Over a battery of cognitive tests, indomethacin patients improved 1.3% (+/- 1.8%), whereas placebo patients declined 8.4% (+/- 2.3%)--a significant difference (p < 0.003). Caveats include adverse reactions to indomethacin and the limited scale of the trial.

Implicit and explicit memory following anterior communicating artery aneurysm rupture.

Several tasks examined the status of implicit and explicit memory in three patients with a ruptured anterior communicating artery (ACoA) aneurysm, one patient with bilateral temporal lobe damage sustained from herpes encephalitis (HE), 12 Alzheimer's disease (AD) patients, and 16 elderly normal controls demographically matched to the AD patients. All subjects completed word stem-completion repetition priming, pursuit-rotor tracking, and a fragmented pictures test, followed by explicit memory tests. ACoA, HE, and AD patients were impaired on all explicit tests. HE and AD patients were impaired on stem-completion priming, but were intact on other implicit tests. ACoA patients were intact on all implicit tests given. Discussion of these results considers similarities and differences in extent of basal forebrain and temporal lobe damage.