Target-absent Conditions Research Articles

Reward delays quitting in visual search.

Reward motivates goal-directed behaviors, leading to faster reaction time (RT) and lower error rate in searching for a target in the reward condition than in the no-reward condition in target-discrimination tasks. However, it is unclear how reward influences target detection in which participants are required to judge whether a predesignated target is present or absent. Here, we asked participants to complete a target-detection search task in which the color of the search array indicated the reward availability of the current trial. Correct and faster (than a baseline) responses would be rewarded if the search array had the reward-related color. In Experiments 1A and 1B, the target was presented in 50% of the trials. Experiment 1B had the same design as Experiment 1A, except that different baselines were set for the target-present and target-absent conditions. In Experiment 2, the proportion of target presence was manipulated to be high (80%), moderate (50%), or low (20%) in different blocks of stimuli. Results showed that, across all the experiments, participants responded faster and made fewer errors in the reward than in the no-reward condition when the target was present. However, this facilitatory effect was reversed when the target was absent, showcasing a reward-induced interference. The signal detection analysis suggested that reward biased the report criterion to the "yes" response. These findings demonstrate that the impact of reward on goal-directed behavior can be detrimental and reward prolongs the search process by rendering participants reluctant to say "no" in visual search termination.

Sensitivity to Semantic Relationships in U.S. Monolingual English-Speaking Typical Talkers and Late Talkers.

Late talkers (LTs) are a group of children who exhibit delays in language development without a known cause. Although a hallmark of LTs is a reduced expressive vocabulary, little is known about LTs' processing of semantic relations among words in their emerging vocabularies. This study uses an eye-tracking task to compare 2-year-old LTs' and typical talkers' (TTs') sensitivity to semantic relationships among early acquired words. U.S. monolingual English-speaking LTs (n = 21) and TTs (n = 24) completed a looking-while-listening task in which they viewed two images on a screen (e.g., a shirt and a pizza), while they heard words that referred to one of the images (e.g., Look! Shirt!; target-present condition) or a semantically related item (e.g., Look! Hat!; target-absent condition). Children's eye movements (i.e., looks to the target) were monitored to assess their sensitivity to these semantic relationships. Both LTs and TTs looked longer at the semantically related image than the unrelated image on target-absent trials, demonstrating sensitivity to the taxonomic relationships used in the experiment. There was no significant group difference between LTs and TTs. Both groups also looked more to the target in the target-present condition than in the target-absent condition. These results reveal that, despite possessing smaller expressive vocabularies, LTs have encoded semantic relationships in their receptive vocabularies and activate these during real-time language comprehension. This study furthers our understanding of LTs' emerging linguistic systems and language processing skills. https://doi.org/10.23641/asha.23303987.

Visual search and childhood vision impairment: A GAMLSS-oriented multiverse analysis approach

The aim of this report was to analyze reaction times and accuracy in children with a vision impairment performing a feature-based visual search task using a multiverse statistical approach. The search task consisted of set sizes 4, 16, and 24, consisting of distractors (circle) and a target (ellipse) that were presented randomly to school-aged individuals with or without a vision impairment. Interactions and main effects of key variables relating to reaction times and accuracy were analyzed via a novel statistical method blending GAMLSS (generalized additive models for location, scale, and shape) and distributional regression trees. Reaction times for the target-present and target-absent conditions were significantly slower in the vision impairment group with increasing set sizes (p < .001). Female participants were significantly slower than were males for set sizes 16 and 24 in the target-absent condition (p < .001), with male participants being significantly slower than females in the target-present condition (p < .001). Accuracy was only significantly worse (p = .03) for participants less than 14 years of age for the target-absent condition with set sizes 16 and 24. There was a positive association between binocular visual acuity and search time (p < .001). The application of GAMLSS with distributional regression trees to the analysis of visual search data may provide further insights into underlying factors affecting search performance in case-control studies where psychological or physical differences may influence visual search outcomes.

Involvement of the dorsal and ventral attention networks invisual attention span.

Visual attention span (VAS), which refers to the window size of multielement parallel processing in a short time, plays an important role in higher‐level cognition (e.g., reading) as required by encoding large amounts of information input. However, it is still a matter of debate about the underlying neural mechanism of VAS. In the present study, a modified visual 1‐back task was designed by using nonverbal stimuli and nonverbal responses, in which possible influences of target presence and position were considered to identify more pure VAS processing. A task‐driven functional magnetic resonance imaging (fMRI) experiment was then performed, and 30 healthy adults participated in this study. Results of confirmatory and exploratory analyses consistently revealed that both dorsal attention network (DAN) and ventral attention network (VAN) were significantly activated during this visual simultaneous processing. In particular, more significant activation in the left superior parietal lobule (LSPL), as compared to that in the bilateral inferior frontal gyrus (IFGs), suggested a greater involvement of DAN in VAS‐related processing in contrast to VAN. In addition, it was also found that the activation in temporoparietal junctions (TPJs) were suppressed during multielement processing only in the target‐absent condition. The current results suggested the recruitment of LSPL in covert attentional shifts and top‐down control of VAS resources distribution during the rapid visual simultaneous processing, as well as the involvement of bilateral IFGs (especially RIFG) in both VAS processing and inhibitory control. The present findings might bring some enlightenments for diagnosis of the atypicality of attentional disorders and reading difficulties.

Contextual cueing in target absent trials by distractor-distractor associations.

Contextual cueing refers to finding a target more efficiently in repeated displays than in novel displays. However, conflicting results have been reported regarding whether target absent judgments can also be efficient in repeated displays. To resolve this controversy, we first tested 3 factors that might influence the strength of distractor-distractor associations and then investigated how such associations produced faster responses on repeated target absent trials by measuring the patterns of eye movements. The factors were the number of distractors, number of repeated configurations, and diversity of the distractors' properties. In Experiments 1 and 2, we found that the diversity of the distractors was the only factor producing contextual cueing without a target. In Experiment 3, we recorded eye movements during a search task and found that the contextual cueing effect in the target absent condition was due to the lower number of fixations and larger mean saccadic amplitudes. Overall, these results suggest that the distractor-distractor associations, strengthened by the diversity of the distractors' properties, widened the attentional window. This enlarged window in turn helps people to reject more distractors at once and enables them to terminate a visual search faster in repeated target absent trials. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

Poorer Search Efficiency in Healthy Young Adults With High Schizotypal Personality Traits.

Perceptual organization (PO) difficulties have repeatedly been reported in people with schizophrenia, and in healthy individuals with high levels of schizotypy traits, who are at increased risk for schizophrenia. In particular, poor performance on the Embedded Figures Test (EFT) has been interpreted as an atypically strong preference for global over local processing, even though these processes cannot be clearly disambiguated on this test. Here we use two separate versions of the Radial Frequency Search Task (RFST), a new index of PO abilities, to selectively investigate global and local processing of shape information in trait schizotypy. Schizotypy traits were assessed using the Wisconsin Schizotypy Scales-Brief. Individuals selected for high and low levels of positive schizotypy [assessed with the Wisconsin Schizotypy Scales-Brief Perceptual Aberration (PAb) scale] completed the EFT, along with the Global RFST and the Local RFST, all of which require participants to find a target shape amongst distractor elements. The High PAb group (n = 83) were less efficient (i.e., reactions times slowed more as the set size increased) than the Low PAb group (n = 146) on the Global RFST (significant group differences for Target Absent conditions only), but not the Local RFST. High and Low PAb groups also differed on other schizotypy traits, so the specificity of the results to positive schizotypy cannot be assured. Unexpectedly, no group differences were observed on the EFT; however, there was a small, but significant, positive correlation between RFST search efficiency and EFT performance, indicating that they shared some common processes. Overall, the pattern of results suggests that global (but not local) processing difficulties may be contributing to the poorer perceptual organization observed in groups with high levels of schizotypy traits. In addition, the confinement of this result to the Target Absent condition suggests that the underlying mechanism involves differences in decisional processes on the RFST between high and low schizotypy groups. The RFST shows promise as a useful tool for measuring specific perceptual organization abilities in non-clinical, and potentially clinical, samples.

Monitoring Processes in Visual Search Enhanced by Professional Experience: The Case of Orange Quality-Control Workers.

Visual search tasks have often been used to investigate how cognitive processes change with expertise. Several studies have shown visual experts' advantages in detecting objects related to their expertise. Here, we tried to extend these findings by investigating whether professional search experience could boost top-down monitoring processes involved in visual search, independently of advantages specific to objects of expertise. To this aim, we recruited a group of quality-control workers employed in citrus farms. Given the specific features of this type of job, we expected that the extensive employment of monitoring mechanisms during orange selection could enhance these mechanisms even in search situations in which orange-related expertise is not suitable. To test this hypothesis, we compared performance of our experimental group and of a well-matched control group on a computerized visual search task. In one block the target was an orange (expertise target) while in the other block the target was a Smurfette doll (neutral target). The a priori hypothesis was to find an advantage for quality-controllers in those situations in which monitoring was especially involved, that is, when deciding the presence/absence of the target required a more extensive inspection of the search array. Results were consistent with our hypothesis. Quality-controllers were faster in those conditions that extensively required monitoring processes, specifically, the Smurfette-present and both target-absent conditions. No differences emerged in the orange-present condition, which resulted to mainly rely on bottom-up processes. These results suggest that top-down processes in visual search can be enhanced through immersive real-life experience beyond visual expertise advantages.

Monitoring mechanisms in visual search: An fMRI study

This fMRI study investigates the neural underpinning and the cognitive factors associated with monitoring in visual search. A visual search task was designed by pseudo-randomly mixing four experimental conditions, which were obtained through the factorial combination of salience (pop-out vs. non pop-out) and target presence (present vs. absent). The fastest responses were obtained when a salient target was presented, while responses were slowest with target-absent conditions, which required extensive evaluation of the visual scene. Partial Least Square multivariate analysis was used to analyze the fMRI data. The first Latent Variable revealed a set of fronto-parietal and occipital regions, which was cohesively activated especially when the presence of the target stimulus was not easy to discard, such as when all stimuli in the visual scene were non-targets or when one stimulus among the rest was salient (pop-out) but not a target. The most extensive and robust activation within this cohesive set of regions was located in the right inferior/middle frontal gyrus. This finding corroborates evidence in favor of a role of the right lateral prefrontal cortex, and associated regions, for evaluative operations, extending previous findings to the visual search domain.

EFFECTS OF COMPETING LEXICAL DISTRACTERS IN A VISUAL SEARCH TASK

ABSTRACTStudies have shown that distracters that are relevant to a target can negatively affect visual search performance. Recent studies have looked at performance when targets are embedded within a distracter. Various factors have been explored such as automaticity, spatial location and timing. This study asked, If distracters affected a different dimension would that produce a detriment to visual search performance? Would competition for attention occur if distracters were on an irrelevant dimension such as lexicality? The results of this study suggest that lexicality, as demonstrated by word frequency, is a disruptive distracter dimension. This study also showed that two distracters of different word frequencies can serve to disrupt attentional capture.Keywords: Lexical Distracter, Attention Capture, Visual Search1. INTRODUCTIONThis experiment expanded on a previous examination of word frequency effects in visual search tasks (Grabbe, 2014) by allowing a simultaneous comparison of distracter words with embedded targets and distracter words without embedded targets within the same trial. This facilitated a greater examination of comparative word frequency effects as distracters (example, the target could be embedded within a low frequency word in a letter string which also contains a high frequency word).This study will answer the question: If there was a proximity effect that disrupted the effect of lexicality, would the distracter influence of lexicality still be disruptive when proximity (embeddedness) is also a factor. This will allow a thorough examination of holistic effects of distracter words on the target search task. Grabbe showed an advantage for targets embedded within a word and the reverse word frequency effect. This study will examine the proximity dimension of distracters by utilizing targets embedded within a word and have an additional, nonembedded distracter word.Hypothesis 1A holistic bias will lead to longer reaction time for targets embedded within high frequency words.Hypothesis 2High frequency distracter words will cause a greater distraction than low frequency words. Therefore longer reaction times will be observed for high frequency word distracters.2. MATERIALS AND METHODS2.1. ParticipantsNineteen participants were recruited from psychology courses at the State University of New York, Plattsburgh. The age range was from 21 to 51 years of age. All participants were screened for normal or corrected-to-normal visions. Informed consent was obtained from all participants.2.2. ProcedureParticipants completed a visual search task in which they searched for a target letter within a letter string. The target letter was presented before each trial. In the experiment all targets were embedded within a word or nonword in a letter string. Each letter string also had a second word which served as a distracter and did not have an embedded target.For the purpose of clarity the distracter in which a target is embedded (which can be a word or nonword) will be referred to as the first distracter and the distracter that does not contain an embedded target (which is always a word) is referred to as the second distracter. Example, the target is the letter L and the letter string is XRATOHOLEYSDT. In that letter string the target appears is embedded in the first distracter (the word hole) while the word rat serves as the second distracter (Fig. 1).Participants completed 10 practice trials before completing 600 experiment trials. Target present trials were composed of three word frequency categories. Each word frequency category for first distracters contained 160 trials of nonreplaced words along with second distracters that were spread equally across word frequency category. Words from word frequency database of Brysbaert and New (2009) were used in this experiment in the target absent condition, no letter string contained a legal, English word. …

The “other-accent” effect in voice recognition

The current paper examines an “other-accent” effect when recognising voices. English and Scottish listeners were tested with English and Scottish voices using a sequential lineup method. The results suggested greater accuracy for own-accent voices than for other-accent voices under both target-present and target-absent conditions. Moreover, self-rated confidence in response to target-absent lineups suggested greater confidence for own-accent voices than other-accent voices. As predicted, the other-accent effect noted here emerged more strongly for English listeners than for Scottish listeners, and these results are discussed within an expertise framework alongside both other-race effects in face recognition, and other-accent effects in word recognition. Given these results, caution is advised in the treatment of earwitness evidence when recognising a voice of another accent.

Hearing Sensation Levels of Emitted Biosonar Clicks in an Echolocating Atlantic Bottlenose Dolphin

Emitted biosonar clicks and auditory evoked potential (AEP) responses triggered by the clicks were synchronously recorded during echolocation in an Atlantic bottlenose dolphin (Tursiops truncatus) trained to wear suction-cup EEG electrodes and to detect targets by echolocation. Three targets with target strengths of −34, −28, and −22 dB were used at distances of 2 to 6.5 m for each target. The AEP responses were sorted according to the corresponding emitted click source levels in 5-dB bins and averaged within each bin to extract biosonar click-related AEPs from noise. The AEP amplitudes were measured peak-to-peak and plotted as a function of click source levels for each target type, distance, and target-present or target-absent condition. Hearing sensation levels of the biosonar clicks were evaluated by comparing the functions of the biosonar click-related AEP amplitude-versus-click source level to a function of external (in free field) click-related AEP amplitude-versus-click sound pressure level. The results indicated that the dolphin's hearing sensation levels to her own biosonar clicks were equal to that of external clicks with sound pressure levels 16 to 36 dB lower than the biosonar click source levels, varying with target type, distance, and condition. These data may be assumed to indicate that the bottlenose dolphin possesses effective protection mechanisms to isolate the self-produced intense biosonar beam from the animal's ears during echolocation.

Population Activity in the Human Dorsal Pathway Predicts the Accuracy of Visual Motion Detection

A person's ability to detect a weak visual target stimulus varies from one viewing to the next. We tested whether the trial-to-trial fluctuations of neural population activity in the human brain are related to the fluctuations of behavioral performance in a "yes-no" visual motion-detection task. We recorded neural population activity with whole head magnetoencephalography (MEG) while subjects searched for a weak coherent motion signal embedded in spatiotemporal noise. We found that, during motion viewing, MEG activity in the 12- to 24-Hz ("beta") frequency range is higher, on average, before correct behavioral choices than before errors and that it predicts correct choices on a trial-by-trial basis. This performance-predictive activity is not evident in the prestimulus baseline and builds up slowly after stimulus onset. Source reconstruction revealed that the performance-predictive activity is expressed in the posterior parietal and dorsolateral prefrontal cortices and, less strongly, in the visual motion-sensitive area MT+. The 12- to 24-Hz activity in these key stages of the human dorsal visual pathway is correlated with behavioral choice in both target-present and target-absent conditions. Importantly, in the absence of the target, 12- to 24-Hz activity tends to be higher before "no" choices ("correct rejects") than before "yes" choices ("false alarms"). It thus predicts the accuracy, and not the content, of subjects' upcoming perceptual reports. We conclude that beta band activity in the human dorsal visual pathway indexes, and potentially controls, the efficiency of neural computations underlying simple perceptual decisions.

The eyes have it: visual pop‐out in infants and adults

Visual search studies with adults have shown that stimuli that contain a unique perceptual feature pop out from dissimilar distractors and are unaffected by the number of distractors. Studies with very young infants have suggested that they too might exhibit pop-out. However, infant studies have used paradigms in which pop-out is measured in seconds or minutes, whereas in adults pop-out occurs in milliseconds. In addition, with the previous infant paradigms the effects from higher cognitive processes such as memory cannot be separated from pop-out and selective attention. Consequently, whether infants exhibit the phenomenon of pop-out and have selective attention mechanisms as found in adults is not clear. This study was an initial attempt to design a paradigm that would provide a comparable measure between infants and adults, thereby allowing a more accurate determination of the developmental course of pop-out and selective attention mechanisms. To this end, we measured 3-month-olds' and adults' saccade latencies to visual arrays that contained either a + among Ls (target-present) or all Ls (target-absent) with set sizes of 1, 3, 5 or 8 items. In Experiment 1, infants' saccade latencies remained unchanged in the target-present conditions as set size increased, whereas their saccade latencies increased linearly in the target-absent conditions as set size increased. In Experiment 2, adults' saccade latencies in the target-present and target-absent conditions showed the same pattern as the infants. The only difference between the infants and adults was that the infants' saccade latencies were slower in every condition. These results indicate that infants do exhibit pop-out on a millisecond scale, that it is unaffected by the number of distractors, and likely have similar functioning selective attention mechanisms. Moreover, the results indicate that eye movement latencies are a more comparable and accurate measure for assessing the phenomenon of pop-out and underlying attentional mechanisms in infants.

Visual search deficits in Parkinson's disease are attenuated by bottom-up target salience and top-down information

Patients with Parkinson's disease (PD), a degenerative disorder primarily affecting the nigrostriatal dopamine system, exhibit deficits in selecting task-relevant stimuli in the presence of irrelevant stimuli, such as in visual search tasks. However, results from previous studies suggest that these deficits may vary as a function of whether selection must rely primarily on the “bottom-up” salience of the target relative to background stimuli, or whether “top-down” information about the identity of the target is available to bias selection. In the present study, moderate-to-severe medicated PD patients and age-matched controls were tested on six visual search tasks that systematically varied the relationship between bottom-up target salience (feature search, noisy feature search, conjunction search) and top-down target knowledge (Target Known versus Target Unknown). Comparison of slope and intercepts of the RT × set size function provided information about the efficiency of search and non-search (e.g., decision, response) components, respectively. Patients exhibited higher intercepts than controls as bottom-up target salience decreased, however these deficits were disproportionately larger under Target Unknown compared to Target Known conditions. Slope differences between PD and controls were limited to the Target Unknown Conjunction condition, where patients exhibited a shallower slope in the target absent condition, indicating that they terminated search earlier. These results suggest that under conditions of high background noise, medicated PD patients were primarily impaired in decision and/or response processes downstream from the target search itself, and that the deficit was attenuated when top-down information was available to guide selection of the target signal.

Earwitnesses: effects of accent, retention and telephone

An experiment was conducted to investigate the effects of accent, telephone and a relatively long retention interval (3 or 8 weeks) on speaker identification. Three-hundred and sixty participants heard the target's voice and were asked to identify the target by means of a line-up consisting of 6 voices. Half of the participants were given a target-present line-up and the other half a target-absent line-up. The results showed that 24% of participants correctly identified the target in the target-present condition (hits), whereas 50% of participants incorrectly identified a person as the target in the target-absent condition (false alarms). The speaker with the standard-accented voice was more often correctly recognized than the speaker with the non-standard-accented voice. No difference was found between identification accuracy after one, three or eight weeks and between the telephone and non-telephone conditions. It can be concluded that there is a relatively high probability that an innocent defendant is identified as the perpetrator, even in a procedurally correct voice line-up (in this experiment 8%). Furthermore, reliability may be drastically reduced when the perpetrator has a strong accent, unfamiliar to the listener. On the other hand, reliability of a voice line-up seems not to be affected by a presentation over the telephone, as well as by a retention interval of at least 8 weeks.

Eyewitness accuracy rates in police showup and lineup presentations: a meta-analytic comparison.

Meta-analysis is used to compare identification accuracy rates in showups and lineups. Eight papers were located, providing 12 tests of the hypothesis and including 3013 participants. Results indicate that showups generate lower choosing rates than lineups. In target present conditions, showups and lineups yield approximately equal hit rates, and in target absent conditions, showups produce a significantly higher level of correct rejections. False identification rates are approximately equal in showups and lineups when lineup foil choices are excluded from analysis. Dangerous false identifications are more numerous for showups when an innocent suspect resembles the perpetrator. Function of lineup foils, assessment strategies for false identifications, and the potential impact of biases in lineup practice are suggested as additional considerations in evaluation of showup versus lineup efficacy.

Improving the identification accuracy of senior witnesses: do prelineup questions and sequential testing help?

Eyewitness research has identified sequential lineup testing as a way of reducing false lineup choices while maintaining accurate identifications. The authors examined the usefulness of this procedure for reducing false choices in older adults. Young and senior witnesses viewed a crime video and were later presented with target present orabsent lineups in a simultaneous or sequential format. In addition, some participants received prelineup questions about their memory for a perpetrator's face and about their confidence in their ability to identify the culprit or to correctly reject the lineup. The sequential lineup reduced false choosing rates among young and older adults in target-absent conditions. In target-present conditions, sequential testing significantly reduced the correct identification rate in both age groups.

Visual search for single and combined features by children and adults: possible developmental inferences.

Visual search time was measured in four groups of children 4 to 10 years of age and in young adults, as a function of display size for both target present and target-absent conditions. The slopes of regression lines in a simple search (search for \ within /) were compared with those obtained in within-dimension conjunction target searches, within either homogeneous (search for the inverted T within Ts) or heterogeneous distractors (search for arrow within Ys and inverted Ys). Analysis indicated that simple search was always preattentive (slopes near 0) after 5 years of age and serial (with positive slopes) before this age. Searching within heterogeneous distractors apparently involved element-by-element scrutiny and focal attention in all groups whereas searching within homogeneous distractors required distributed attention, perhaps based on parallel grouping of distractors in adults, though distractors were focally attended to by children.

Facial composite production: A comparison of mechanical and computer-driven systems.

Computer-driven systems for constructing composite faces of suspects (E-fit; Mac-a-Mug) have largely replaced mechanical systems (Photofit; the Identikit) in police use, yet little is known of their comparative effectiveness in rendering an accurate likeness. Participants (N = 24) constructed 2 of 4 familiar or unfamiliar faces, for one of which they used Photofit and for the other, E-fit. A likeness of each face was made first under target-absent conditions and then with photographs of the target present. The accuracy of the resulting composites was assessed by familiarity ratings, names elicited, and matching accuracy. The computer-driven system showed consistent superiority only when a familiar face was constructed in the presence of photographs; when participants worked from memory, E-fit was no better than Photofit. The implications of these findings for theories of face retrieval and the operational use of composites are discussed.