Functional connectivity during monitoring for visuomotor incongruence.

Previous human studies on monitoring for visuomotor incongruence emphasized the contribution of the fronto-parietal network and revealed significant activation of the right dorsolateral prefrontal cortex (DLPFC) and the right rostral inferior parietal lobule. Using functional MRI, this study investigated the brain regions involved in explicit monitoring for incongruence between motor intention and visual and/or proprioceptive information, particularly focusing on the fronto-parietal network. During in-phase bimanual movements, a static image of the participant's own hands was randomly inserted within real-time visual feedback of the movements to produce a mismatch between the actual performance and the visual input. The results of our task were similar to those of previous studies, in that greater activity was observed in the right DLPFC during incongruence conditions than during congruence conditions. However, the anatomical location of the DLPFC cluster was found in a more ventral region, compared with previous studies. Psychophysiological interaction analysis for the entire brain, using the right DLPFC as a seed region, indicated significantly greater functional connectivity with the bilateral dorsal premotor cortex, middle temporal gyri (area V5), and right rostral inferior parietal lobule (area PFt).

Social cognition in schizophrenia: similarities and differences of emotional perception from patients with focal frontal lesions.

The structural and functional abnormalities of the frontal lobes, the region implicated in social information processing, have been suspected to underlie social cognitive impairments in schizophrenia. However, multiple structures, including the limbic/paralimbic areas that are also important for social cognition, have been reported to be abnormal in schizophrenia. The aim of this study is to investigate the extent to which the frontal lobe dysfunction accounts for social cognitive impairments in schizophrenia by comparing with patients who have focal frontal lobe injuries. Social cognitive abilities, focusing on affective aspects, were examined by an emotion intensity recognition task, which is sensitive to the amygdala function, and the emotion attribution tasks, which rely mainly on the frontal lobe function. Individuals with schizophrenia were impaired on the emotion intensity recognition task as well as on the emotion attribution tasks as compared with healthy subjects. By contrast, the frontal lobe-damaged group was defective in the emotion attribution tasks but not in the emotion intensity recognition task. Our results indicated that social cognitive impairments observed in schizophrenia can be accounted for partly by their frontal lobe pathology. Other aspects of social cognitive impairments could also be associated with the extra-frontal pathology, such as the amygdala.

Retrieval by a patient with apraxia of sensorimotor information from visually presented objects.

Motor representations are reported to be implicitly evoked when one observes manipulatable objects (action potentiation). The relationship was examined between action potentiation and pantomime deficit in apraxia. Participants responded to line drawings of manipulatable objects with either the left or right hand, according to the color of the stimulus. In normal participants (N= 10, four women, six men, M age = 28.5 yr., SD = 5.6), responses were faster when the orientation of the stimulus was compatible with the response-hand grasp. However, the apraxic patient did not exhibit this compatibility effect. On a control task in which a nonobject (circle) was presented, all participants exhibited the compatibility effect. These results indicated that the apraxic patient was impaired in evoking motor representation associated with objects. Thus, in some cases, apraxic disorders may be attributable to a deficit in retrieving object-specific information for manipulation.

Subtemporal hippocampectomy preserving the basal temporal language area for intractable mesial temporal lobe epilepsy: preliminary results.

PURPOSE: Decline in verbal memory as a surgical complication remains an unresolved problem in mesial temporal lobe epilepsy. Some areas in the temporal lobe associated with the language function, often including the basal temporal language area, have been removed or transected by conventional surgical procedures. The authors defined the basal temporal language area and removed only the epileptogenic zone with a subtemporal approach. METHODS: The basal temporal language area was evaluated by using long-term subdural electrodes in five patients with language-dominant-side mesial temporal lobe epilepsy. While preserving this area, the hippocampus and the parahippocampal gyrus were removed by using a combined subtemporal, transventricular, transchoroidal fissure approach. Verbal memory performance was assessed with the Wechsler Memory Scale-Revised (WMS-R) before and after the operation. RESULTS: The basal temporal language area, defined as a part of the inferior temporal gyrus, the fusiform gyrus, and the parahippocampal gyrus, was spared by entering the temporal horn via collateral sulcus. Verbal memory was significantly improved by 3 months and 1 year after the operation. CONCLUSIONS: In language-dominant-side mesial temporal lobe epilepsy, preserving the basal temporal language area would have potential to improve verbal memory outcomes after removal of the epileptogenic zone.

[Novel advances in neuropsychology--forward to the "deconstruction" of psychiatry].

Neuropsychology has recently become a science which deals not only with instrumental disorders (e.g., aphasia, apraxia, and agnosia), but also with impairments of interpersonal relationships (e.g., emotional cognitions, social decision making, and understanding others), and many important paradigms are already provided. We could enumerate several representative instances: (1)application of the "theory of mind" to autistic or related disorders (-->"reasoning of psychological state of others"), (2) neuropsychological studies on the "social brain" concerning emotional recognition or social recognition (-->"amygdale, orbitofrontal cortex, and medial ventral frontal cortex"), (3) identifying related cerebral areas (-->"superior temporal sulcus") to detect eye or body movements of others, (4) discovering the mirror neuron and mirror systems in monkeys and humans (-->"imitation of the behavior of others in the brain"), and (5) intracerebral processes which may occur precedent to conscious intention (-->"consciousness as post-hoc phenomena"). These novel paradigms might lead us to the "deconstruction" of psychiatry. We believe that the fundamental assignments of neuropsychology should inquire into "cognitive representation", "conscious representation", and "cerebral representation" about the inner processes of human activities. As these assignments would be almost the same for the psychiatric symptoms, we do not have any necessity to fundamentally distinguish psychiatric and neuropsychologial symptoms. These two kinds of signs will be attributed finally to the same dimension. The specificity of psychiatry resides in "conscious representation" and its cerebral foundations. We reconsidered the "Theory of Neural Group Selection" proposed by Edelman and the excellent experimental results on the relationship between intention and movements reported by Libet, et al.. All these results strongly indicate the absolute necessity to reconsider conscious causality and psychogenesis. Finally, we have presented two main neuropsychological hypotheses on the manifestation mechanism of Capgras syndrome. These are the "mirror impairment of prosopagnosia" hypothesis and the "self-other confusion resulting from right hemisphere dysfunction" hypothesis. We insisted on the importance of the right cerebral predominance hypothesis about self-other understanding processes and also the absolute necessity to shake ourselves free from language dependent consciousness theory. Common specificity in neuropsychology and psychiatry should be converged to, and symbolized by the novel concept of sociality, which is characterized for instance by emotional cognition or social decision making supported by the social brain and by shared cerebral representations for self-other understanding and consciousness processes.

Emotion recognition from facial expressions in a temporal lobe epileptic patient with ictal fear.

Ictal fear (IF) is an affective aura observed in patients with temporal lobe epilepsy. It has been suggested that the amygdala, a region implicated in emotion processing, is involved in generating IF. Several studies have reported that the patients with IF have disturbances in emotional experience, but there has been no testing of the emotional recognition in those patients. In this report, emotion recognition from facial expressions was investigated in a patient with IF. The patient suffered from IF due to temporal lobe epilepsy, and underwent hippocampectomy surgery which completely suppressed IF. We examined the patient before and after surgery. Before surgery, the patient tended to attach enhanced fear, sadness, and anger to various facial expressions. After surgery, such biases disappeared. As an underlying mechanism of the pre-surgical skewed perception of emotional stimuli, the abnormal epileptogenic circuits involving a hypersensitive amygdala possibly due to the kindling mechanism were suggested.

[Writing Kanji without semantics in a case with probable Alzheimer's disease].

We examined a patient (NM) with probable Alzheimer's disease who showed phonologically plausible errors in kanji (logogram) writing. In semantic tasks, she showed no deficits in pointing or naming but had difficulty in more complex tasks such as proverb comprehension. In reading aloud of kanji words, she could read most kanji words correctly and showed little phonologically plausible reading errors. She performed poorly in lexical decision and on-reading of one-letter kanji (Sino-Japanese pronunciation derived from the Chinese language at the time of borrowing). Writing to dictation demonstrated no mistakes in kana letters and words, but many errors in kanji, which were phonologically equivalent but semantically inappropriate. To explore the relationship between the writing errors in kanji words and comprehension of the word meanings, we selected 33 words that she made phonologically plausible writing errors. We gave her the following five tasks using these words; 1) to ask meanings of the words, 2) to dictate the words, 3) to dictate sentences including these words, 4) to discriminate appropriate target words from distracters including her own erroneous responses, and 5) to write these words again. She showed no consistent errors in these tasks. In some occasions, she could write correct kanji words without understanding word meanings. She also showed phonologically plausible writing errors in spite of describing correct word meanings. In Japanese, word meaning deficits like Gogi aphasia were thought to cause phonologically plausible writing errors. As the impairments of word meanings in NM are comparatively mild, the underpinning of her kanji agraphias might be different from that of phonologically plausible errors in Gogi aphasia. It would be suggested that she frequently wrote phonologically equivalent errors because of her lexical deficits in spite that her phonological processing was preserved. Furthermore, she would not necessarily use the semantics (word meanings) of kanji words during dictation.