Kevin Dent

Age of Acquisition and Word Frequency Effects in Picture Naming: A Dual-Task Investigation

In 2 experiments, the authors explored age of acquisition (AoA) and word frequency (WF) effects in picture naming using the psychological refractory period paradigm. In Experiment 1, participants named a picture and then, a short time later, categorized 1 of 3 possible auditory tones as high, medium, or low. Both AoA (Experiment 1A) and WF (Experiment 1B) effects propagated onto tone discrimination reaction times (RTs), with the effects of AoA being stronger. In Experiment 2, the to-be-named picture followed the auditory tone by a varying interval. As the interval decreased, picture naming RTs increased. The relationship between the interval and AoA (Experiment 2A) was reliably underadditive; AoA effects were eliminated at the shortest interval. In contrast, WF (Experiment 2B) was additive with the effects of the interval. These results demonstrate an empirical dissociation between AoA and WF effects. AoA affects processing stages that precede those that are sensitive to WF. The implications for theories of picture naming are discussed.

Dynamic Visual Noise Affects Visual Short-Term Memory for Surface Color, but not Spatial Location

In two experiments participants retained a single color or a set of four spatial locations in memory. During a 5 s retention interval participants viewed either flickering dynamic visual noise or a static matrix pattern. In Experiment 1 memory was assessed using a recognition procedure, in which participants indicated if a particular test stimulus matched the memorized stimulus or not. In Experiment 2 participants attempted to either reproduce the locations or they picked the color from a whole range of possibilities. Both experiments revealed effects of dynamic visual noise (DVN) on memory for colors but not for locations. The implications of the results for theories of working memory and the methodological prospects for DVN as an experimental tool are discussed.

Age of acquisition, not word frequency affects object recognition: Evidence from the effects of visual degradation

Four experiments examined how age of acquisition (AoA) and word frequency (WF) interact with manipulations of image quality in a picture-naming task. Experiments 1 and 2 examined the effect of overlaying the to-be-named picture with irrelevant contours. The magnitude of the AoA effect increased when the contours were added (Experiment 1), but the effect of WF remained constant (Experiment 2). Experiments 3 and 4 examined the effects of reducing the contrast of the contours defining the to-be-named picture. Both the effects of AoA (Experiment 3) and WF (Experiment 4) remained constant in the face of contrast reduction. These results provide an empirical dissociation of the effects of AoA and WF. The results are consistent with the idea that both AoA and the addition of irrelevant contours affect the efficiency of object recognition, but WF affects later processes involved in retrieval of object names. The theoretical implications of these findings in relation to accounts of AoA and frequency and their functional localisation in the lexical system are discussed.

Parallel distractor rejection as a binding mechanism in search.

The relatively common experimental visual search task of finding a red X amongst red O’s and green X’s (conjunction search) presents the visual system with a binding problem. Illusory conjunctions (ICs) of features across objects must be avoided and only features present in the same object bound together. Correct binding into unique objects by the visual system may be promoted, and ICs minimized, by inhibiting the locations of distractors possessing non-target features (e.g., Treisman and Sato, 1990). Such parallel rejection of interfering distractors leaves the target as the only item competing for selection; thus solving the binding problem. In the present article we explore the theoretical and empirical basis of this process of active distractor inhibition in search. Specific experiments that provide strong evidence for a process of active distractor inhibition in search are highlighted. In the final part of the article we consider how distractor inhibition, as defined here, may be realized at a neurophysiological level (Treisman and Sato, 1990).

New perspectives on perspective-taking mechanisms and the out-of-body experience.

The out-of-body experience (OBE) can be defined as “.an experience in which a person seems to perceive the world from a location outside his physical body.” (Blackmore, 1982; p. 1). A growing number of studies have investigated OBEs, their underlying substrates, and kindred hallucinatory phenomena of the ‘self’ (i.e., autoscopy/heautoscopy/sensed-presence experiences) to inform a more comprehensive understanding of the wider issues of illusory self-reduplication (see Arzy et al., 2006; Brugger, 2002; Brugger et al., 1997). As well as providing a framework for understanding striking experiences in fields such as clinical neurology, such research is also informing current neuroscientific accounts for stable ‘in-the-body’ processing aswell. As a consequence of these developments, it has been suggested that the varieties of self-reduplication experiences (including the OBE), may represent different experiential manifestations fromacontinuumofdisintegration of the self in space (Brugger, 2002). Recently, a number of studies have argued that the brain processes involved in the mental transformation of one’s own body may be the same as those implicated in the computation of the exocentric-perspective reported in the OBE (Arzy et al., 2006; Blanke et al., 2005; Easton et al., 2009; Mohr et al., 2006). All these studies are united in that they employed variations of the “Own-Body-Transformation” task (OBT task) to assess perspective-taking performance (see Blanke et al., 2005). The task requires the observer to report on which hand a manikin avatar is wearing a distinctive glove and bracelet. The typical finding from these studies is that there is a cost in reaction time for trials when the perspective of the avatar differs from that of the observer (situations which presumably require some form of body-transformation and/or perspective-taking). Specifically the OBT task has been shown to recruit brain regions (i.e., the

Capacity limitations and representational shifts in spatial short-term memory

Performance was examined in a task requiring the reconstruction of spatial locations. Previous research suggests that it may be necessary to differentiate between memory for smaller and larger numbers of locations (Postma & DeHaan, 1996), at least when locations are presented simultaneously (Igel & Harvey, 1991). Detailed analyses of the characteristics of performance showed that such a differentiation might also be required for sequential presentation. Furthermore the slope of the function relating each successive response to accuracy was greater with 3 than with 6, 8, or 10 locations that did not differ. Participants also reconstructed the arrays as being more proximal than in fact they were; sequential presentation eliminated this distortion when there were three but not when there were more than three locations. These results support the idea that very small numbers of locations are remembered using a specific form of representation, which is unavailable to larger numbers of locations.

Age of acquisition, word frequency, and picture–word interference

In two experiments participants named pictures superimposed with unrelated words. The age of acquisition (AoA) of the picture names was manipulated. Additionally, the word frequency (WF, Experiment 1) or AoA (Experiment 2) of the interfering distractor words was manipulated. Early-acquired pictures were named faster than their late-acquired counterparts. Both WF and AoA modulated the degree of interference from the irrelevant word; low-frequency and late-acquired words produced most interference. In neither case did the WF or AoA of the distractor word interact with the AoA of the picture. The results show that in the context of word processing both WF and AoA have similar effects.

Age of acquisition affects early orthographic processing during Chinese character recognition

Three experiments investigated age of acquisition (AoA) effects on early orthographic processing during Chinese character recognition. In Experiment 1, we measured the accuracy of identification of brief masked characters, accuracy was higher for early compared to late acquired characters. In Experiment 2, the visual duration threshold (VDT) was measured for both early and late acquired Chinese characters. The results showed that early acquired characters were successfully identified at shorter display durations than late acquired characters. Significant AoA effects were also found in Experiment 3, using a lexical decision task requiring mainly orthographic processing (discriminating real Chinese characters from orthographically illegal and unpronounceable characters). In summary, three experiments provide converging empirical evidence, for AoA effects on the early orthographic processing stages of Chinese character recognition. These results suggest that AoA effects during word identification go beyond the phonological or semantic processing stages. These results aslo provide cross-linguistic evidence for an AoA effect on early perceptual processing during identification.

British-English norms and naming times for a set of 539 pictures: The role of age of acquisition

In the present study, we presented picture-naming latencies along with ratings for a set of important characteristics of pictures and picture names: age of acquisition, frequency, picture-name agreement, name agreement, visual complexity, familiarity, and word length. The validity of these data was established by calculating correlations with previous studies. Regression analyses show that our ratings account for a larger amount of variance in RTs than do previous data. RTs were predicted by all variables except complexity and length. A complete database presenting details about all of these variables is available in the supplemental materials, downloadable from http://brm.psychonomic-journals.org/content/supplemental.

Deficits in visual search for conjunctions of motion and form after parietal damage but with spared hMT+/V5

It has been argued that area hMT+/V5 in humans acts as a motion filter, enabling targets defined by a conjunction of motion and form to be efficiently selected. We present data indicating that (a) damage to parietal cortex leads to a selective problem in processing motion–form conjunctions, and (b) that the presence of a structurally and functional intact hMT+/V5 is not sufficient for efficient search for motion–form conjunctions. We suggest that, in addition to motion-processing areas (e.g., hMT+/V5), the posterior parietal cortex is necessary for efficient search with motion–form conjunctions, so that damage to either brain region may bring about deficits in search. We discuss the results in terms of the involvement of the posterior parietal cortex in the top-down guidance of search or in the binding of motion and form information.