PubMed Health⌕ Search

Biomedical subjects

Hans J Markowitsch

Publications and source records attributed to Hans J Markowitsch.

22 records · Page 2Linked to original sources
PubMed2003

Cognitive estimation and affective judgments in alcoholic Korsakoff patients.

Alcoholic Korsakoff patients have their most marked deficits in memory, but may exhibit problems in further cognitive and behavioral domains, particularly in so-called frontal lobe functions and on the emotional level. Cognitive estimation is among the frontal lobe-associated functions; nevertheless, the underlying processes of estimation and estimation deficits are still unknown. Additionally, though affective judgments were found to be disturbed in Korsakoff patients one can question whether this result is due to a deficiency in emotional processing itself, or whether deteriorated basic processes underlying all kinds of judgment tasks result in affective judgment errors. In this study, possible relations and underlying cognitive processes of affective and nonaffective judgments (cognitive estimates) were analyzed in a large sample of 39 Korsakoff patients. A neuropsychological test battery was administered together with a new test for cognitive estimation consisting of four dimensions ('size,' 'weight,' 'quantity,' and 'time') and an affective judgment task comprising negative, neutral, and positive words. The Korsakoff patients' results showed marked deficits concerning both, cognitive estimation and affective judgments. These deficits were highly intercorrelated and performance in both tasks was related to basic (e.g., information processing speed) and higher cognitive functions (executive functions and memory), suggesting a common basis in cognitive estimation and in affective judgments in Korsakoff syndrome.

Aged↗
PubMed2003

Differential remoteness and emotional tone modulate the neural correlates of autobiographical memory.

Autobiographical memory relies on complex interactions between episodic memory contents, associated emotions and a sense of self-continuity along the time axis of one's life history. The neural correlates underlying autobiographical memory are known to primarily comprise areas of prefrontal cortex, medial and lateral temporal cortex, as well as posterior cingulate and retrosplenial cortex. By contrast, the effect of encoding and/or storage parameters such as the emotional tone of the memories retrieved or the length of the time-interval between the initial encoding of information and retrieval remains to be clarified. Using blocked design functional MRI and statistical parametric mapping, we investigated the impact of remoteness (factor 1: recent, remote) and emotional valence (factor 2: positive, negative) on the neural correlates of autobiographical memory retrieval. Changes in neural activity (P < 0.05, corrected) related to autobiographical memory retrieval (irrespective of remoteness and emotional tone) relative to baseline were observed bilaterally in medial and lateral temporal, temporal-occipital, posterior cingulate and frontal cortices. Recent (relative to remote) memories were associated with differentially increased neural activity bilaterally in the retrosplenial cortex and the hippocampal region, whereas remote (relative to recent) memories did not show any statistically significant differential neural activations. Positive (relative to negative) memories bilaterally activated the orbitofrontal cortex, the temporal pole, as well as medial temporal areas, with the activation peak being in the entorhinal region. By contrast, negative (relative to positive) memories differentially increased neural activity in the right middle temporal gyrus only. The data suggest differential functional roles for temporal, prefrontal and retrosplenial regions during autobiographical memory retrieval depending on the remoteness and the emotional valence of the memories retrieved. In particular, our findings support the 'classic' model of long-term memory processing, which suggests a time-limited differential involvement of the hippocampus in memory consolidation. Interestingly, the observation of such a time-dependent involvement of the hippocampal region in memory consolidation corresponds to the course of retrograde amnesia observed in demented patients, with the loss of recent memories appearing during early stages of the disease when conspicuous neurofibrillary changes are restricted mainly to the hippocampal and parahippocampal regions. Only during later stages, as the neurofibrillary changes spread out to neocortical association areas, do remote memories also become impaired. We conclude that the brain regions involved in autobiographical memory retrieval are influenced by the triggered memories' emotional significance and their relationship to the individual time axis.

Adult↗
PubMedDate not supplied

Engagement of lateral and medial prefrontal areas in the ecphory of sad and happy autobiographical memories.

Autobiographic memory is usually affect-laden, either positively or negatively. A central question is whether the retrieval of both emotive forms of memory engages the same or a different neural net. To test this we studied 13 normal subjects with functional magnetic resonance imaging while they retrieved a number of distinct episodes, all of which were either rated as strongly positive (happy) or strongly negative (sad) in affect. Comparing the retrieval of sad with that of happy episodes revealed activation in both lateral orbital cortices symmetrically (extending into the ventrolateral prefrontal cortex as well), together with a small region in the right lateral temporal cortex and the left cerebellum. Vice versa, comparing the retrieval of happy with that of sad episodes revealed a major activation in the left hippocampal region, bilateral (though more right-sided) activation in the medial orbitofrontal/subgenual cingulate and a left sided activation in the dorsolateral prefrontal activation. These findings point to the importance of the orbitofrontal cortex for affect-laden information processing and to the existence of distinct neural nets for the re-activation of positively and negatively viewed autobiographic episodes.

Adult↗