Fluency and response speed in recognition judgments

Previous research has suggested that perceptual fluency can contribute to recognition judgments. In this study, we examined whether fluency in recognition is based upon the speed of preceding operations, as suggested by studies of perceptual fluency. Subjects studied items in both lexical decision and naming tasks, and were then tested on two blocks of lexical decision trials with probe recognition trials. Jacoby’s process dissociation procedure was used, and results from this procedure suggested that recognition judgments in the task were based largely upon familiarity. However, the estimated discriminability available from response time distributions was significantly less than the observed recognition discriminability. Simulated memory operating characteristics confirmed this underdetermination of recognition by response times. The results demonstrate, contrary to previous suggestions, that fluency in recognition is not based upon speed.     

A positron emission tomography (PET) study of autobiographical memory retrieval

Memory for the experiences of one's life, autobiographical memory (AM), is one of the most human types of memory, yet comparatively little is known of its neurobiology. A positron emission tomography (PET) study of AM retrieval revealed that the left frontal cortex was significantly active during retrieval (compared to memory control tasks), together with activation in the inferior temporal and occipital lobes in the left hemisphere. We propose that this left frontal lobe activation reflects the operation of control processes that modulate the construction of AMs in posterior neocortical networks.     

A simple,all-mechanical operant apparatus

An apparatus is described that utilizes the force exerted by a rat in turning a wheel to rotate reward cups into his presence after passing through a reservoir containing water or ground mash. The response-ratio requirement, force requirement, and amount of reward can be manipulated by simple adjustment or interchange of parts.     

Executive control of thought and action

In addition to processing information about stimuli in the environment, the cognitive system performs executive functions to control and coordinate the processes that deal with environmental stimuli. Several executive functions may be distinguished: (1) Making choices about alternative strategies for processing environmental stimuli; (2) constructing or instantiating a version of the chosen strategy to enable performance on the task; (3) controlling and coordinating execution of the strategy during real-time performance on the task; and (4) disabling or disengaging the strategy in response to changes in goals or changes in the task environment that make the current strategy inappropriate. This paper presents a selective review of research addressing each of these executive functions, focusing on the time and resources used to accomplish each one.     

Costs and benefits of strategy construction in a speeded discrimination task

The costs and benefits of constructing and utilizing a strategy for performing a speeded discrimination task were assessed in terms of time and mental resources. The strategy involved using information about the position a word occupied in order to respond to its identity more rapidly. The resources used to construct and utilize the strategy were assessed from responses to probes presented at various times during the task. In Experiment 1, the probe required a manual response, whereas in Experiment 2, the probe required a vocal response. Strategy construction interfered with the probe task in Experiment 1 but not in Experiment 2, suggesting that strategy construction required resources specific to the manual response system. There was also some evidence that strategy construction required general resources, but the evidence for specific resources was much stronger. The findings are consistent with our previous ideas about how the strategy is represented (Logan, 1980a; Logan & Zbrodoff, 1979). The different results with different responses to the probes point out important limitations on previous studies of probe interference and of cost-benefit analysis, which each focused on a single dimension of cost and benefit. The differences suggest that a multiple-resources approach to probe interference and cost-benefit analysis might be more appropriate.     

Visibility distances with halogen and conventional headlights

Abstract.— Using visibility distance as a criterion, halogen and conventional continental European high and low-beam headlights were compared in a series of field experiments. On high-beam without opposing light the halogen headlights offered about 25% longer visibility distances than the conventional headlights. With both opposing cars using low-beam there was a slight advantage (<5 m) in favour of halogen headlights. The optimal dipping distance was a function of high-beam system (intensity) rather than low-beam system. Small differences in aiming, atmosphere etc. caused larger differences in visibility distance than did the headlight system.     

The transition from algorithm to retrieval in memory-based theories of automaticity

Two memory-based theories of automaticity were compared. The mixture model and the race model both describe automatization as a transition from algorithmic processing to memory retrieval. The mixture model predicts that, with training, the variability of reaction time will initially increase, and later decrease in a concave downward manner, whereas the race model predicts the variability will decrease only in a concave upward manner. The mixture model predicts that using both algorithm and retrieval on a single trial will be slower than using the algorithm alone, whereas the race model predicts the reverse. The experiments used an alphabet arithmetic task, in which subjects verified equations of the form H + 3 = K and made subjective reports of their strategies on individual trials. Both the variability of reaction times and the pattern of reaction times associated with the strategy reports supported the race model.     

On the nature of talker variability effects on recall of spoken word lists.

In a recent study, Martin, Mullennix, Pisoni, and Summers (1989) reported that subjects' accuracy in recalling lists of spoken words was better for words in early list positions when the words were spoken by a single talker than when they were spoken by multiple talkers. The present study was conducted to examine the nature of these effects in further detail. Accuracy of serial-ordered recall was examined for lists of words spoken by either a single talker or by multiple talkers. Half the lists contained easily recognizable words, and half contained more difficult words, according to a combined metric of word frequency, lexical neighborhood density, and neighborhood frequency. Rate of presentation was manipulated to assess the effects of both variables on rehearsal and perceptual encoding. A strong interaction was obtained between talker variability and rate of presentation. Recall of multiple-talker lists was affected much more than single-talker lists by changes in presentation rate. At slow presentation rates, words in early serial positions produced by multiple talkers were actually recalled more accurately than words produced by a single talker. No interaction was observed for word confusability and rate of presentation. The data provide support for the proposal that talker variability affects the accuracy of recall of spoken words not only by increasing the processing demands for early perceptual encoding of the words, but also by affecting the efficiency of the rehearsal process itself.