Exhausting attentional tracking resources with a single fast-moving object

Driving on a busy road, eluding a group of predators, or playing a team sport involves keeping track of multiple moving objects. In typical laboratory tasks, the number of visual targets that humans can track is about four. Three types of theories have been advanced to explain this limit. The fixed-limit theory posits a set number of attentional pointers available to follow objects. Spatial interference theory proposes that when targets are near each other, their attentional spotlights mutually interfere. Resource theory asserts that a limited resource is divided among targets, and performance reflects the amount available per target. Utilising widely separated objects to avoid spatial interference, the present experiments validated the predictions of resource theory. The fastest target speed at which two targets could be tracked was much slower than the fastest speed at which one target could be tracked. This speed limit for tracking two targets was approximately that predicted if at high speeds, only a single target could be tracked. This result cannot be accommodated by the fixed-limit or interference theories. Evidently a fast target, if it moves fast enough, can exhaust attentional resources.     

Practice effects on two memory retrievals from a single cue

The effects of practice on 2 retrievals from a single cue were investigated. In Experiment 1, participants were given extended single-task practice and were then tested on a dual memory retrieval task. Perfomance was consistent with a sequential retrieval model proposed by T. C. Rickard and H. Pashler (2003). In Experiment 2, participants practiced both single- and dual-retrieval tasks extensively. Initially, data from all participants indicated sequential retrieval. However, participants who grouped the 2 response outputs were eventually able to perform the dual task with a latency that approached the prediction of a parallel race model. Models that assume a transition from sequential to parallel retrieval with practice, along with other models that assume an immutable retrieval bottleneck at all practice levels, are considered.     

Semantic priming effects from single words in a lexical decision task

The present research examines the semantic priming effects of a centrally presented single prime word to which participants were instructed to either "attend and remember" or "ignore". The prime word was followed by a central probe target on which the participants made a lexical decision task. The main variables manipulated across experiments were prime duration (50 or 100 ms), the presence or absence of a mask following the prime, and the presence (or absence) and type of distractor stimulus (random set of consonants or pseudowords) on the probe display. There was a consistent interaction between the instructions and the semantic priming effects. Relative to the "attend and remember" instruction, an "ignore" instruction produced reduced positive priming from single primes presented for 100 ms, irrespective of the presence or absence of a prime mask, and regardless of whether the probe target was presented with or without distractors. Additionally, reliable negative priming was found from ignored primes presented for briefer durations (50 ms) and immediately followed by a mask. Methodological and theoretical implications of the present findings for the extant negative priming literature are discussed.     

Transfer effects in a problem solving context

In recent years hypothesis theory has been applied to transfer between problems and thus used to explain a variety of transfer phenomena. A version of the theory is presented which leads to the prediction that identical variations in identical problems can lead to opposite trends in speed of solution of a critical problem depending on the nature of that problem. Using numerical tasks it was demonstrated that identical variations in preliminary problems either can transform a normally simple problem into an insoluble one or alternatively an insoluble problem into a simple one with the only alteration being in the degree of similarity between the hypotheses required for the initial problems and the critical problem. Implications for Einstellung, the sequence effect and general problem solving are discussed.     

Transfer effects from language processing to visual attention dynamics: The impact of orthographic transparency

The consistency between letters and sounds varies across languages. These differences have been proposed to be associated with different reading mechanisms (lexical vs. phonological), processing grain sizes (coarse vs. fine) and attentional windows (whole words vs. individual letters). This study aimed to extend this idea to writing to dictation. For that purpose, we evaluated whether the use of different types of processing has a differential impact on local windowing attention: phonological (local) processing in a transparent language (Spanish) and lexical (global) processing of an opaque language (English). Spanish and English monolinguals (Experiment 1) and Spanish–English bilinguals (Experiment 2) performed a writing to dictation task followed by a global–local task. The first key performance showed a critical dissociation between languages: the response times (RTs) from the Spanish writing to dictation task was modulated by word length, whereas the RTs from the English writing to dictation task was modulated by word frequency and age of acquisition, as evidence that language transparency biases processing towards phonological or lexical strategies. In addition, after a Spanish task, participants more efficiently processed local information, which resulted in both the benefit of global congruent information and the reduced cost of incongruent global information. Additionally, the results showed that bilinguals adapt their attentional processing depending on the orthographic transparency.     

Unifying representations and responses: perseverative biases arise from a single behavioral system

Abstract— A dominant account of perseverative errors in early development contends that such errors reflect a failure to inhibit a prepotent response. This study investigated whether perseveration might also arise from a failure to inhibit a prepotent representation. Children watched as a toy was hidden at an A location, waited during a delay, and then watched the experimenter find the toy. After six observation-only A trials, the toy was hidden at a B location, and children were allowed to search for the toy. Two- and 4-year-olds' responses on the B trials were significantly biased toward A even though they had never overtly responded to this location. Thus, perseverative biases in early development can arise as a result of prepotent representations, demonstrating that the prepotent-response account is incomplete. We discuss three alternative interpretations of these results, including the possibility that representational and response-based biases reflect the operation of a single, integrated behavioral system.     

Repetition priming effects from attended vs. ignored single words in a semantic categorization task

The present research examines priming effects from a centrally presented single-prime word to which participants were instructed to either attend or ignore. The prime word was followed by a single central target word to which participants made a semantic categorization (animate vs. inanimate) task. The main variables manipulated across experiments were attentional instructions (attend vs. ignore the prime word), presentation duration of the prime word (20, 50, 80 or 100 ms), prime-target stimulus onset asynchrony (SOA; 300 vs. 800 ms), and temporal presentation of instructions (before vs. after the prime word). The results showed (a) a consistent interaction between attentional instructions and repetition priming and (b) a qualitatively different ignored priming pattern as a function of prime duration: reduced positive priming (relative to the attend instruction) for prime exposures of 80 and 100 ms, and reliable negative priming for the shorter prime exposures of 20 and 50 ms. In addition (c), the differential priming pattern for attend and ignore trials was observed at a prime-target SOA of 800 ms (but not at a shorter 300-ms SOA) and only when instructions were presented before the prime word. Methodological and theoretical implications of the present findings for the extant negative priming literature are discussed.     

Transfer of therapeutic effects from institution to home: faith, hope, and behavior modification.

Effective transfer of therapeutic results from institutional to home settings is a demanding problem facing family therapists. The issues involved and one approach to their solution are examined through the case of a 10-year-old boy hospitalized for severe antisocial behavior. Once results were obtained in an institutional setting, the therapeutic program there was faded out and concurrently faded into the home. Three- and 12-month follow-ups revealed continued improvement.     

Compatibility effects in stopping and response initiation in a continuous tracking task

Two experiments explored stopping performance using a new stimulus–response compatibility effect spanning action initiation and stopping. Participants tracked a sometimes-moving, sometimes-stationary target by controlling the speed of a response marker via a force sensor. In the compatible condition, participants pressed the sensor in response to the target moving and stopped pressing in response to the target stopping. In the incompatible condition, participants stopped pressing in response to the target moving and initiated pressing in response to the target stopping. Response initiation and stopping were found to be faster under compatible than under incompatible conditions, regardless of whether compatible and incompatible trials were blocked or mixed. These findings indicate that stopping, like response initiation, is influenced by stimulus–response properties such as compatibility. This in turn suggests that stopping is governed by constraints similar to those of other behaviours.     

Compatibility effects in stopping and response initiation in a continuous tracking task

Two experiments explored stopping performance using a new stimulus-response compatibility effect spanning action initiation and stopping. Participants tracked a sometimes-moving, sometimes-stationary target by controlling the speed of a response marker via a force sensor. In the compatible condition, participants pressed the sensor in response to the target moving and stopped pressing in response to the target stopping. In the incompatible condition, participants stopped pressing in response to the target moving and initiated pressing in response to the target stopping. Response initiation and stopping were found to be faster under compatible than under incompatible conditions, regardless of whether compatible and incompatible trials were blocked or mixed. These findings indicate that stopping, like response initiation, is influenced by stimulus-response properties such as compatibility. This in turn suggests that stopping is governed by constraints similar to those of other behaviours.     

Spatial compatibility interference effects: a double dissociation between two measures

ABSTRACT

In spatial compatibility tasks, when the spatial location of a stimulus is irrelevant it nevertheless interferes when a response is required in a different spatial location. For example, response with a left key-press is slowed when the stimulus is presented to the right as compared to the left side of a computer screen. However, in some conditions this interference effect is not detected in reaction time (RT) measures. It is typically assumed that the lack of effect means the irrelevant spatial code was not analysed or that the information rapidly decayed before response. However, we show that even in conditions where there appears to be no spatial interference when measuring RTs, effects can nevertheless be detected after response when recording facial electromyography responses. This dissociation between two measures highlights the importance of diverging methods to investigate visuomotor processes as conclusions based on only one measure can be misleading.     

Egocentric spatial framework effects from single and multiple points of view

In three experiments, we tested the one-place, one-perspective rule formulated by Franklin, Tversky, and Coon (1992). This rule proposes that subjects take a neutral, external perspective when they must use multiple viewpoints to make decisions about the locations of objects in memorized scenes. We compared responding from a single viewpoint with responding from two viewpoints. In Experiments 1 and 2, we used a sentence verification procedure, and in Experiment 3, we compared a true-false verification procedure with a six-alternative forced-choice procedure. Under these various conditions, we observed egocentric spatial framework effects in that above-below judgments were faster than front-back judgments and front-back judgments were faster than right-left judgments. When responding from two points of view in a single place, our subjects took multiple intrinsic perspectives rather than one neutral external perspective as proposed by the one-place, one-perspective rule.     

The human operator as a single channel information system

A further experiment is reported on reaction times to stimuli separated by short intervals. On this occasion an auditory stimulus was followed by a visual stimulus. Results indicate that the pattern of delays at short intervals is the same as the pattern of delays when the stimuli are presented in one modality only. This suggests a model of the human operator functioning as a single channel through which information from both sense modalities has to pass before appropriate responses are organized. An attempt is also made to reconcile data with the known facts about the peripheral and central components of reaction time and the possibility that delays are the result of occupation of the channel for a central time plus a central refractory time is suggested.