Forms of memory failure in schizophrenia.

Effortful and automatic memory task performances were examined in 36 schizophrenic patients and 18 normal control Ss. Tasks included free recall, recognition, and frequency estimation. Patients demonstrated impairment in recall, in recognition, in semantic encoding, and in frequency estimation. Deficits were observed across tasks despite differences in attentional demands. The results suggest a basic compromise of memory function, which is consistent with recent neuroimaging evidence of structural or physiological abnormalities in frontal and temporal lobe structures in schizophrenia.     

Toward the neural basis of verbal priming: A cognitive-neuropsychological synthesis

Repetition priming is a mnemonic phenomenon that has attracted considerable attention from neuropsychologists and cognitive scientists. In an attempt at elucidating the putative mechanisms of priming, the present review draws on evidence from both domains. The review is restricted to verbal priming of visually presented stimuli—an area that accounts for the majority of empirical studies of priming. A number of theoretical accounts are presented. The interim conclusion is that neither multiple systems nor unitary system-multiple process theories can adequately explain the data on priming, although both contain many valid components. An integrative model is proposed to improve the explanation of the empirical evidence. The central assertion of the proposed model is that repetition priming depends on perceptual processes that can be mapped on specific neural systems. It is postulated that individual differences in perceptual processing ability predict variability in memory performance. It is proposed that data-driven priming of verbal stimuli critically depends on the activity of primary and secondary visual cortices in the right hemisphere, whereas conceptually-driven priming is hypothesized to rely on the activities of higher order tertiary association cortices in language areas and more anterior neocortical areas.     

CS-specific gamma,theta, and alpha EEG activity detected in stimulus generalization following induction of behavioral memory by stimulation of the nucleus basalis

Tone paired with stimulation of the nucleus basalis (NB) induces behavioral memory that is specific to the frequency of the conditioned stimulus (CS), assessed by cardiac and respiration behavior during post-training stimulus generalization testing. This paper focuses on CS-specific spectral and temporal features of conditioned EEG activation. Adult male Sprague-Dawley rats, chronically implanted with a stimulating electrode in the NB and a recording electrode in the ipsilateral auditory cortex, received either tone (6kHz, 70dB, 2s) paired with co-terminating stimulation of the nucleus basalis (0.2s, 100Hz, 80-105 microA, ITI approximately 45s) or unpaired presentation of the stimuli (approximately 200 trials/day for approximately 14 days). CS-specificity was tested 24h post-training by presenting test tones to obtain generalization gradients for the EEG, heart rate, and respiration. Behavioral memory was evident in cardiac and respiratory responses that were maximal to the CS frequency of 6kHz. FFT analyses of tone-elicited changes of power in the delta, theta, alpha, beta1, beta2, and gamma bands in the paired group revealed that conditioned EEG activation (shift from lower to higher frequencies) was differentially spectrally and temporally specific: theta, and alpha to a lesser extent, decreased selectively to 6kHz during and for several seconds following tone presentation while gamma power increased transiently during and after 6kHz. Delta exhibited no CS-specificity and the beta bands showed transient specificity only after several seconds. The unpaired group exhibited neither CS-specific behavioral nor EEG effects. Thus, stimulus generalization tests reveal that conditioned EEG activation is not unitary but rather reflects CS-specificity, with band-selective markers for specific, associative neural processes in learning and memory.     

The Hasidic Ethos and the Schisms of Jewish Society

The early hasidic movement was distinguished by its readiness to see the sacred in everything. As presented by Rabbi Yaakov Yosef of Polonnoye (d. 1782), disciple of the Baal Shem Tov, this perception was particularly to be applied to fragmented eastern European Jewish society. The scholarly class saw themselves as “holy” but could not relate to the ignorant masses. Hasidic teachings sought to reveal the holiness in everyone and thus draw together these disparate classes, with a vision of an underlying unity of the Jewish people. During the nineteenth century, the Enlightenment and Reformist movements provoked a strong traditionalist reaction which eventually led to the contemporary ultra-orthodox (haredi) enclave. The haredi Jew consciously seeks to live in a separate society with invisible walls protecting the holiness within and keeping at bay the profane world outside. The hasidim form an important section of this haredi enclave, deliberately suppressing the earlier inclusivist hasidic ethos. In the mid-twentieth century, the Habad hasidic movement revived aspects of that ethos in a modern form, leading to its dominant contemporary mode of expression: outreach. At the same time, Habad seeks to remain part of the haredi world. This post-modern combination of opposites may eventually influence other haredi groups and lead to new configurations of the schisms provoked by the confrontation of tradition and modernity.     

Submerged electrodes in an aquarium: Validation of a technique for remote sensing of behavior

Necturus maculosus has been selected as representative of a class of neotenic amphibia whose behavior (including gill beat, heartbeat, and tail waving) can be sensed remotely by submerged electrodes in an aquarium. This communication presents a validation of the technique as a preface to reports on the electrophysiology of behavior in unrestrained surgically naive salamanders. Although the sources of the submarine signals are not known with certainty, they apparently depend on two factors: (1) aquarium water of appropriate ionic strength serves as a volume conductor for activity, and (2) animal movement displaces water or produces waves which are sensed as a change in potential at the water-electrode interface. This method provides a continuous comprehensive record of behavior simultaneously from several response systems in a freely behaving animal.