View-based theories of the mental representation of spatial information claim that distinct views experienced during learning are represented separately in memory. Networks of such views are considered to be the basis for spatial navigation. Two experiments (N = 56) investigated the role of observer perspective on the resulting mental representation when learning a spatial configuration on the computer. Learning in route perspective, which induced the impression of passive navigation through the configuration, was compared with a survey perspective, which consisted of an overview of the whole configuration from one point of view. In accordance with view-based theories, previously seen views could be identified faster and with less error than new views for both perspectives during learning. Recoding the information into the alternative perspective was also possible. If participants were asked to integrate distinct route views into a survey view during learning, the flexibility of the resulting mental representation was greatly increased. This indicates that conscious processes such as imagery play an important role in the integration of spatial knowledge.
Based on the integration of the memory advantage for subject-performed actions into the multimodal theory of episodic memory by J. Engelkamp (1997), three issues referring to the so-called enactment effect are discussed and addressed by statistical r-analyses. Firstly, the empirical basis of the functional distinction between motor and non-motor memory resources by means of dual-task experiments is questioned. Secondly, a multinomial modeling analysis is presented which aims at the contributions of automatic and controlled memory processes to the enactment effect in the process-dissociation paradigm. Finally, the effect of enactment on memory for serial order information is discussed with respect to recent accounts of serial memory.
In two laboratory experiments (N1 = 84, N2 = 20) the impact of goal setting on information processing (perception) in letter-matching tasks was examined. It was expected that setting difficult goals for reaction times improves performance because identification and especially semantic classification of letters should be speeded up under goal-setting instructions. Three findings can be emphasized. (1) Current models of simultaneous letter matching are incomplete because they do not account for differences in reaction time based on alphabetic variations (lower case vs. upper case letters) within a pair of letters that are largely independent of real letter sizes. (2) In both experiments and for all types of letter pairs (AA, Aa, Ab AB), goal-setting effects are found as expected. In addition, the explanation that these effects are due to a speed-accuracy trade-off can be excluded. (3) Moreover, in some conditions goal-setting effects are also influenced by special features of letter pairs. Specifically, goal-setting effects are especially strong for letter pairs in which the right letter was enlarged and in which alphabetic differences and semantic differences within pairs call for opposite answers (Aa, AB). Based on the overall pattern of results, it is concluded that difficult goals lead to a general facilitation of processes in visual perception and, in addition, to a reduction of stimulus-induced, performance-delaying inhibition processes if linguistic information is processed predominantly in the left hemisphere.
A model proposed by Thüring (1991) for inferences based on causal knowledge was empirically tested. According to this model, two variables affect the certainty with which a causal inference is concluded: insufficiency (model-specific uncertainty) and ambiguity (situation-specific uncertainty). Within an experiment these two variables were manipulated. Both had a very significant (p < .01) influence on causal inferences. In respect to its quantity, variation of ambiguity had the effect predicted in the model. Concerning insufficiency, distinct differences between predicted and empirical ratings were found. Reasons for these deviations and model modifications resulting therefrom are discussed.
The paper deals with the study of remembering episodes and particularly with German contributions to the field. It is characteristic for remembering episodes that we experience them only once and not repeatedly as in multitrial learning. The paper focuses on three distinctions which are made in studying episodic memory. These distinctions refer to modality-specific and amodal (conceptual) information, item-specific and relational information, and automatic and controlled processes. Among them, the distinction between modality-specific and amodal conceptual information is the most important. It is argued that the assumption of storing modality-specific besides conceptual information is indispensable and that it modifies the assumptions concerning the two other distinctions. Relational information refers to conceptual knowledge and is independent of modality-specific information processing, whereas encoding and retrieval of item-specific information is dependent on modality-specific processes. The distinction between automatic and controlled processes is obviously relevant. However, it turns out that this distinction is difficult to define conceptually and operationally. Interestingly, this distinction has attracted more attention in the context of retrieval than of encoding processes. The most important progress has been made in applying it to the processes underlying recognition memory.
An experimental study investigated the joint influence of priming and situational cues on the perceived neediness of a target. A scrambled sentence test was used to prime two groups with the concepts of neediness and safety. In a third group a neutral concept was activated. A free description of the target and a subsequent adjective rating were applied as dependent measures. Although results indicated that both factors affected the attribution of neediness on a free description, the effects of priming were only apparent on this measurement and disappeared on the second task.
Posner proposed a theory of attention based on target detection, visual orienting, and alertness. The latter is supposed to use brain structures mainly located in the right hemisphere. Whitehead found a right hemisphere processing superiority during sustained attention. An additional auditory stimulus is thought to produce a change of alertness and should interfere with this asymmetry, which Whitehead was able to show, too. It remains unclear how the left hemisphere is activated by right hemisphere pathways. Therefore we tried to replicate Whitehead's findings. In our first experiment the expected interaction between visual field, foreperiod duration, and tone was obtained. Probably the tone used in our experiment was not intense enough to produce a sufficient change in alertness. We used a more intense tone in a second experiment. This time a three-way interaction was present but could not be interpreted in terms of Whitehead's assumptions. Instead, the additional alerting stimulus seems to influence the state of alertness in a much more general and long-lasting way.
Synchronized neural activity in animal visual cortex in the frequency range above 20 Hz, the gamma band, has been proposed as a signature of temporal feature binding. More and more research in humans by means of noninvasive electrophysiological recordings was stimulated by these studies. Here, research on evoked and induced gamma band activity in human EEG and MEG mainly in the auditory and visual modality is reviewed and their role in perceptual processes, feature integration and language processing is discussed. In addition, research on the attentional modulation of gamma band activity is reviewed. In contrast to evoked gamma band activity, which occurs right after stimulus onset, induced gamma band activity can be recorded with a latency of 200 to 400 ms and a frequency range of 30 to 95 Hz. Cumulative consistent experimental evidence allows us to conclude that gamma band activity in the human cortex is related to neuronal information processing and cognitive functions, e.g. memory processes. The findings are discussed in the light of different functional theories of induced gamma band activity.