A phase transition model for the speed-accuracy trade-off in response time experiments

Most models of response time (RT) in elementary cognitive tasks implicitly assume that the speed-accuracy trade-off is continuous: When payoffs or instructions gradually increase the level of speed stress, people are assumed to gradually sacrifice response accuracy in exchange for gradual increases in response speed. This trade-off presumably operates over the entire range from accurate but slow responding to fast but chance-level responding (i.e., guessing). In this article, we challenge the assumption of continuity and propose a phase transition model for RTs and accuracy. Analogous to the fast guess model (Ollman, 1966), our model postulates two modes of processing: a guess mode and a stimulus-controlled mode. From catastrophe theory, we derive two important predictions that allow us to test our model against the fast guess model and against the popular class of sequential sampling models. The first prediction--hysteresis in the transitions between guessing and stimulus-controlled behavior--was confirmed in an experiment that gradually changed the reward for speed versus accuracy. The second prediction--bimodal RT distributions--was confirmed in an experiment that required participants to respond in a way that is intermediate between guessing and accurate responding.     

Decision-making in robotics and psychology: A distributed account

Decision-making is usually a secondary topic in psychology, relegated to the last chapters of textbooks. The psychological study of decision-making assumes a certain conception of its nature and mechanisms that has been shown wrong by research in robotics. Robotics indicate that decision-making is not—or at least not only—an intellectual task, but also a process of dynamic behavioral control, mediated by embodied and situated sensorimotor interaction. The implications of this conception for psychology are discussed.     

Linking impulsivity and inhibitory control using manual and oculomotor response inhibition tasks

Separate cognitive processes govern the inhibitory control of manual and oculomotor movements. Despite this fundamental distinction, little is known about how these inhibitory control processes relate to more complex domains of behavioral functioning. This study sought to determine how these inhibitory control mechanisms relate to broadly defined domains of impulsive behavior. Thirty adults with attention-deficit/hyperactivity disorder (ADHD) and 28 comparison adults performed behavioral measures of inhibitory control and completed impulsivity inventories. Results suggest that oculomotor inhibitory control, but not manual inhibitory control, is related to specific domains of self-reported impulsivity. This finding was limited to the ADHD group; no significant relations between inhibitory control and impulsivity were found in comparison adults. These results highlight the heterogeneity of inhibitory control processes and their differential relations to different facets of impulsivity.     

The premotor theory of attention and the Simon effect

In the paper by Hommel (2011-this issue), the roles of the theory of event coding (TEC) and the premotor theory of attention (PMTA) for the Simon effect were considered. PMTA was treated by Hommel in terms of the proposal that attentional orienting can be viewed as the preparation of a saccade towards a certain location, and was dismissed as providing no useful contribution for an attentional explanation of the Simon effect. Here we considered a more recent and broader conception of the PMTA, compared this approach with TEC, and confronted both approaches with a few studies focusing on the role of spatial attention for the Simon effect. It was argued that PMTA may account more easily for various studies examining the influence of spatial attention on the Simon effect. We concluded our paper by listing some elements that an overall encompassing theory on the Simon effect should contain.     

Orthographic neighborhood size effect in Chinese character naming: orthographic and phonological activations

The present study examined the effects of orthographic neighborhood (N) size on the cognitive processes underlying Chinese character reading. Previous research has shown increasing N size facilitates word naming and recognition performance in alphabetic languages. Experiment 1 revealed that a large N size was associated with a general inhibition of processes underlying character reading, in contrast to previous findings with alphabetic languages. This inhibitory effect was influenced by regularity and consistency. Experiment 2 sought to assess the effects of higher-frequency neighbors on character naming performance. The results revealed that higher-frequency neighbors with different pronunciation to the target interfered with the phonological retrieval of targets. We propose that this type of interference may have caused the N size effect observed in Experiment 1. The results of Experiment 3 revealed that a large N size facilitated target naming in the absence of higher-frequency neighbors. The current results shed light on the processes underlying character naming, and we propose possible cognitive mechanisms of the N size effect on Chinese character naming.     

Experience dependent changes in odour-viscosity perception

One consequence of experiencing flavour — the combination of taste, smell and somatosensation that occurs during ingestion — is that it can result in perceptual changes for the odour component, when this is later smelled alone. One such change is the acquisition of taste-like properties, but whether odours can also acquire somatosensory-like qualities is largely unknown. Participants here were exposed to one odour sampled in a viscous solution, another sampled in a sweet/viscous solution, and a further odour sampled in water. The odour sampled in the sweet/viscous solution was, when later sniffed alone, judged to smell thicker and sweeter, than the other two odours. Similarly, when the sweet/viscous paired odour was added to a viscous solution, the combination was judged as more viscous, than the other two odours — and sweeter when added to a sweet solution. This experiment suggests that odours can acquire tactile-like somatosensory qualities and this may best occur when a taste is present during learning. Recent work indicates that tastes may be superior to somatosensory stimuli alone in promoting flavour binding, a seeming precondition for this type of learning.     

Conflict and error adaptation in the Simon task

We present recent empirical and theoretical advances in conflict and error monitoring in the Simon task. On the basis of the adaptation by binding account for conflict adaptation and the orienting account for post-error slowing, we predict a dissociation between conflict and error monitoring. This prediction is tested and confirmed as conflict adaptation is task-specific while post-error slowing is not.     

Attention on our mind: The role of spatial attention in visual working memory

The current study shows that spatial visual attention is used to retrieve information from visual working memory. Participants had to keep four colored circles in visual working memory. While keeping this information in memory we asked whether one of the colors was present in the array. While retrieving this information, on some trials a probe dot was presented. When this probe dot was presented at the location of the color that had to be retrieved, participants responded faster than when it was presented at another location. Our findings further elaborate the role of visual attention in working memory: not only is attention the mechanism by which information is stored into working memory, it is also the mechanism by which information is retrieved from visual working memory.     

Automatic and strategic effects in the guidance of attention by working memory representations

Theories of visual attention suggest that working memory representations automatically guide attention toward memory-matching objects. Some empirical tests of this prediction have produced results consistent with working memory automatically guiding attention. However, others have shown that individuals can strategically control whether working memory representations guide visual attention. Previous studies have not independently measured automatic and strategic contributions to the interactions between working memory and attention. In this study, we used a classic manipulation of the probability of valid, neutral, and invalid cues to tease apart the nature of such interactions. This framework utilizes measures of reaction time (RT) to quantify the costs and benefits of attending to memory-matching items and infer the relative magnitudes of automatic and strategic effects. We found both costs and benefits even when the memory-matching item was no more likely to be the target than other items, indicating an automatic component of attentional guidance. However, the costs and benefits essentially doubled as the probability of a trial with a valid cue increased from 20% to 80%, demonstrating a potent strategic effect. We also show that the instructions given to participants led to a significant change in guidance distinct from the actual probability of events during the experiment. Together, these findings demonstrate that the influence of working memory representations on attention is driven by both automatic and strategic interactions.     

On letter frequency effects

In four experiments we examined whether the frequency of occurrence of letters affects performance in the alphabetic decision task (speeded letter vs. pseudo-letter classification). Experiments 1A and 1B tested isolated letters and pseudo-letters presented at fixation, and Experiments 2A and 2B tested the same stimuli inserted at the 1st, 3rd, or 5th position in a string of Xs. Significant negative correlations between letter frequency and response times to letter targets were found in all experiments. The correlations were found to be stronger for token frequency counts compared with both type frequency and frequency rank, stronger for frequency counts based on a book corpus compared with film subtitles, and stronger for measures counting occurrences as the first letter of words compared with inner letters and final letters. Correlations for letters presented in strings of Xs were found to depend on letter case and position-in-string. The results are in favor of models of word recognition that implement case-specific and position-specific letter representations.