Context-dependent neural responses to minor notes in frontal and temporal regions distinguish musicians from nonmusicians.

Musical training is required for individuals to correctly label musical modes using the terms "major" and "minor," whereas no training is required to label these modes as "happy" or "sad." Despite the high accuracy of nonmusicians in happy/sad labeling, previous research suggests that these individuals may exhibit differences in the neural response to the critical note-the note (the third of the relevant key) that defines a melody as major or minor. The current study replicates the presence of a late positive component (LPC) to the minor melody in musicians only. Importantly, we also extend this finding to examine additional neural correlates of critical notes in a melody. Although there was no evidence of an LPC response to a second occurrence of the critical note in either group, there was a strong early right anterior negativity response in the inferior frontal gyrus in musicians in response to the first critical note in the minor mode. This response was sufficient to classify participants based on their musical training group. Furthermore, there were no differences in prefrontal asymmetry in the alpha or beta bands during the critical notes. These findings support the hypothesis that musical training may enhance the neural response to the information content of critical note in a minor scale but not the neural response to the emotional content of a melody.

Basic response time tools for studying general processing capacity in attention, perception, and cognition.

One of the more important constructs in the study of attention, perception, and cognition is that of capacity. The authors reviewed some of the common meanings of this construct and proposed a more precise treatment. They showed how the distribution of response times can be used to derive measures of process capacity and to further illustrate how these measures can be used to address important hypotheses in cognition.

Spatial frequencies in short-term memory for faces: a test of three frequency-dependent hypotheses.

Spatial frequency manipulations have been shown to have significant utility in ascertaining the various types of information that might be important in object identification and recognition tasks. This utility suggests that, given some mapping between ranges of spatial frequencies and different types of psychological information, it should be possible to examine the roles of these different types of psychological information by way of spatial frequency manipulations. One potential problem, however, is that there is no well-specified, unambiguous mapping between the distinctions in the frequency domain and the distinctions in the informational domain. Three experiments provide tests of three general hypotheses regarding the ways in which different spatial frequencies might map to different information in facial perception and memory tasks: (1) the low-frequency dominance hypothesis, which proposes that low-frequency information should be superior (to high-frequency information) as a cue to perception and memory; (2) the distinct informational roles hypothesis, which holds that high spatial frequencies should carry featural information while low spatial frequencies should carry information about the configuration of those features; and (3) the task-dependent information hypothesis, which suggests that high-frequency information should be best suited to discrimination tasks while low-frequency information should be best suited for recognition tasks. Results generally contradict the first two of these hypotheses, while providing support for the third. Implications with regard to the various issues related to the mapping between spatial frequencies and the informational content of faces, as well as the need to consider important interactions among perceptual and memory processes, are discussed.

On the whats and hows of retrieval in the acquisition of a simple skill.

Two general views on the role of memory in cognitive skills--an instance-based theory and an associative perspective--were compared with respect to their general assumptions about the information involved and the processes that operate on that information. Characteristics of memory information were examined in terms of predictions for transfer to various stimulus forms as a function of 2 types of learning conditions. Characteristics of memory processes were examined using a set of general process models. Results of 4 experiments indicate that (a) neither theoretical perspective was capable of accounting for all the observed transfer effects, indicating needed refinements to informational assumptions, and that (b) 1 class of process assumptions was consistently supported, whereas other classes were consistently contradicted, indicating a general set of process characteristics that can be used in further model development.

Ontogenetic differences in variability on simple measures of learning: theoretical and practical implications.

Data from a variety of sources, including a number of tasks and dependent measures, suggests that a systematic inverse relationship exists between age and the amount of variability observed on simple measures of learning. Implications for general theoretical perspectives concerning ontogenetic differences in stimulus and response selection, acquired knowledge or experience, and general speed of information processing are discussed. It is argued that such a regularity offers possibilities for both methodological and theoretical explorations.

Effects of speech intelligibility level on concurrent visual task performance.

Four experiments were performed to determine if changes in the level of speech intelligibility in an auditory task have an impact on performance in concurrent visual tasks. The auditory task used in each experiment was a memory search task in which subjects memorized a set of words and then decided whether auditorily presented probe items were members of the memorized set. The visual tasks used were an unstable tracking task, a spatial decision-making task, a mathematical reasoning task, and a probability monitoring task. Results showed that performance on the unstable tracking and probability monitoring tasks was unaffected by the level of speech intelligibility on the auditory task, whereas accuracy in the spatial decision-making and mathematical processing tasks was significantly worse at low speech intelligibility levels. The findings are interpreted within the framework of multiple resource theory.

Selective disruption of hypermnesia for pictures and words.

In this study, we investigated the effects of various interpolated tasks on hypermnesia (improved recall across repeated tests) for pictures and words. In five experiments, subjects studied either pictures or words and then completed two free-recall tests, with varying activities interpolated between the tests. The tasks performed between tests were varied to test several hypotheses concerning the possible factor(s) responsible for disruption of the hypermnesic effect. In each experiment, hypermnesia was obtained in a control condition in which there was no interpolated task between tests. The remaining conditions showed that the effect of the interpolated tasks was related to the overlap of the cognitive processes involved in encoding the target items and performing the interpolated tasks. When pictures were used as the target items, no hypermnesia was obtained when subjects engaged in imaginal processing interpolated tasks, even when these tasks involved materials that were very distinct from the target items. When words were used as the target items, no hypermnesia was obtained when the interpolated tasks required verbal/linguistic processing, even when the items used in these tasks were auditorily presented. The results are discussed in terms of a strength-based model of associative memory.

Initial recall, reminiscence, and hypermnesia: comment on Madigan and O'Hara (1992).

S. Madigan and R. O'Hara (1992) analyzed data from repeated free-recall experiments and concluded that the rate of item recovery across tests was related to the level of recall performance on an initial free-recall test. We report a reanalysis of these data along with Monte Carlo simulations that indicate the measures used by Madigan and O'Hara may have inflated the magnitude of the relation between initial recall and item recovery. The results are discussed in terms of their implications for future research investigating reminiscence and hypermnesia.