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.     

Evidence for preserved emotional memory in normal older persons

Emotion has been shown to have a modulatory effect on declarative memory. Normal aging is associated with a decline in declarative memory, but whether aging might affect the influence of emotion on memory has not been established. To investigate this, we administered a task that provides a detailed assessment of emotional memory to 80 neurologically normal adults ranging in age from 35 to 85 years. Across ages, memory performance was found to be modulated by the emotional significance of stimuli in a comparable manner (improved memory for gist, compromised memory for visual detail), despite an overall decline in memory performance with increasing age. The results raise the interesting possibility that aging has a differential effect on hippocampal versus amygdala function.     

Circadian phase-shifted rats show normal acquisition but impaired long-term retention of place information in the water task

It is thought that circadian rhythms may influence learning and memory processes. However, research supporting this view does not dissociate a mnemonic impairment from other performance deficits. Furthermore, published reports do not specify the type of memory system influenced by the circadian system. The present study assessed the effects of phase shifting on acquisition and expression of place navigation in the water maze, a task sensitive to hippocampal dysfunction. The results showed that phase-shifting circadian rhythms in rats impaired the expression of place information on a retention test but not initial acquisition or encoding of place information. These results suggest that disruption of circadian rhythms may impair consolidation of previously encoded hippocampal place information.     

Is a picture worth a thousand words? Evidence from concept definitions by patients with semantic dementia

Nine patients with semantic dementia (the temporal lobe variant of frontotemporal dementia) were asked to define concrete concepts either from presentation of a picture of the object or from its spoken name. As expected, the patients with the most severe semantic impairment produced the least detailed definitions, and the quality of the definitions overall was significantly related to concept familiarity. Further analyses of the definitions were designed to assess two key theoretical aspects of semantic organization. (i) Do objects and their corresponding names activate conceptual information in two neuroanatomically separable (modality-specific) semantic systems? If so, then-apart from any expected commonality in performance attributable to factors such as concept familiarity-one would not predict striking item-specific similarities in a patient's picture- and word-elicited definitions. (ii) Do sensory/perceptual features and more associative/functional attributes of conceptual knowledge form two neuroanatomically separable subsystems? If so, then one would predict significant dissociations in the prominence of these two types of information in the patients' definitions. The results lead us to favor a model of the semantic system that is divided by attribute type but not by modality.     

The Relation between Formal and Informal Logic

The issue of the relationship between formal and informal logic depends strongly on how one understands these two designations. While there is very little disagreement about the nature of formal logic, the same is not true regarding informal logic, which is understood in various (often incompatible) ways by various thinkers. After reviewing some of the more prominent conceptions of informal logic, I will present my own, defend it and then show how informal logic, so understood, is complementary to formal logic.     

Schleiermacher and Spirit Christology: Unexplored Horizons of The Christian Faith

One of the more recent efforts at christological construction has focused on Spirit christology, issuing in sometimes opposing constructions. At first sight, considering Schleiermacher's synthetic approach to the doctrine of the Trinity, one would suspect the irrelevance of his christology for these present efforts. However, an analysis of the convergence between christology and pneumatology in the Glaubenslehre could contribute significantly to this debate. By interpreting the God-consciousness of Jesus as the presence of the Spirit in him and correlating this with the communication of this consciousness as the work of Christ in regeneration and sanctification we achieve an identity between Christ as Spirit-bearer and Spirit-sender (viz. the Redeemer understood according to his 'peculiar activity' and 'exclusive dignity'). By lending a stronger pneumatological bearing to Schleiermacher's theological discourse (picking up the suggestion of Karl Barth) Schleiermacher helps illuminate some of the issues that have arisen in debate over Spirit christology.     

When Good Intentions Are Not Enough: Modeling Postdecisional Cognitive Correlates of Condom Use1

Measures of intention usually leave substantial proportions of the variance in behavior unexplained. It has been suggested that improved behavioral prediction could be achieved by identifying postdecisional cognitive processes capable of distinguishing between intenders who do act and those do not act. Condom-related self-report measures of postdecisional cognitive processes were developed and tested in a cross-sectional questionnaire study involving 447 heterosexual students. A discriminant function composed of postdecisional measures was found to significantly distinguish between intenders who reported use and non-use and to correctly classify 80% of intenders. The results indicate that measures of the relative importance of competing intentions, prior planning of specific preparatory actions, and action-specific self-efficacy may enhance the prediction of condom use among intenders.