Iconic memory and visible persistence

There are three senses in which a visual stimulus may be said to persist psychologically for some time after its physical offset. First, neural activity in the visual system evoked by the stimulus may continue after stimulus offset (“neural persistence”). Second, the stimulus may continue to be visible for some time after its offset (“visible persistence”). Finally, information about visual properties of the stimulus may continue to be available to an observer for some time after stimulus offset (“informational persistence”). These three forms of visual persistence are widely assumed to reflect a single underlying process: a decaying visual trace that (1) consists of afteractivity in the visual system, (2) is visible, and (3) is the source of visual information in experiments on decaying visual memory. It is argued here that this assumption is incorrect. Studies of visible persistence are reviewed; seven different techniques that have been used for investigating visible persistence are identified, and it is pointed out that numerous studies using a variety of techniques have demonstrated two fundamental properties of visible persistence: theinverse duration effect (the longer a stimulus lasts, the shorter is its persistence after stimulus offset) and theinverse intensity effect (the more intense the stimulus, the briefer its persistence). Only when stimuli are so intense as to produce afterimages do these two effects fail to occur. Work on neural persistences is briefly reviewed; such persistences exist at the photoreceptor level and at various stages in the visual pathways. It is proposed that visible persistence depends upon both of these types of neural persistence; furthermore, there must be an additional neural locus, since a purely stereoscopic (and hence cortical) form of visible persistence exists. It is argued that informational persistence is defined by the use of the partial report methods introduced by Averbach and Coriell (1961) and Sperling (1960), and the term “iconic memory” is used to describe this form of persistence. Several studies of the effects of stimulus duration and stimulus intensity upon the duration of iconic memory have been carried out. Their results demonstrate that the duration of iconic memory is not inversely related to stimulus duration or stimulus intensity. It follows that informational persistence or iconic memory cannot be identified with visible persistence, since they have fundamentally different properties. One implication of this claim that one cannot investigate iconic memory by tasks that require the subject to make phenomenological judgments about the duration of a visual display. In other words, the so-called “direct methods” for studying iconic memory do not provide information about iconic memory. Another implication is that iconic memory is not intimately tied to processes going on in the visual system (as visible persistence is); provided a stimulus is adequately legible, its physical parameters have little influence upon its iconic memory. The paper concludes by pointing out that there exists an alternative to the usual view of iconic memory as a precategorical sensory buffer. According to this alternative, iconic memory is post-categorical, occurring subsequent to stimulus identification. Here, stimulus identification is considered to be a rapid automatic process which does not require buffer storage, but which provides no information about episodic properties of a visual stimulus. Information about these physical stimulus properties must, in some way, be temporarily attached to a representation of the stimulus in semantic memory; and it is this temporarily attached physical information which constitutes iconic memory.     

Children’s use of phonological encoding when reading for meaning

The role of phonological recoding in children’s reading was investigated by means of a task requiring comprehension of sentence meaning: The child’s task was to decide whether a sequence of printed letter strings was a meaningful sentence or not. Meaningless sentences that are meaningful when phonologically recoded (e.g., “He ran threw the street”) produced more incorrect responses than did meaningless sentences that remain meaningless when phonologically recoded (e.g., “He ran sew the street”). The difference in error rates between the two sentence types diminished as a function of age. Control experiments showed that these results were not due to visual similarity effects, nor to imperfect ability to spell homophones. It was concluded that very young readers rely extensively on phonological recoding when reading for meaning; as they grow older, reliance on visual encoding becomes progressively more important.     

The role of assembled phonology in reading comprehension

The contribution of assembled phonology to phonological effects in reading comprehension was assessed. In Experiment 1, subjects judged the acceptability of sentences with regular, exception, and nonword homophone substitutions and orthographic controls. Significantly more errors occurred to sentences with regular-word homophones than to exception words, and error rates for nonword homophones were low and not significant. Experiment 2 showed that this was not due to differences in the sentence frames. In Experiment 3, the subjects judged as unacceptable those sentences containing an exception word that sounded correct when read according to spelling-to-sound rules. Significantly higher error rates occurred only for low-frequency exception words. Experiment 4 showed that task conditions affect semantic-categorization error rates for nonword homophones. These results indicate that both assembled and addressed phonology contribute to sentence and word comprehension, but the low error rate for nonwords suggests that an early lexical check may be applied.     

Too exhausted to go to bed: Implicit theories about willpower and stress predict bedtime procrastination

While most people are aware of the importance of sleep for their health, well-being, and performance, bedtime procrastination is a pervasive phenomenon that can be conceptualized as a case of self-control failure (Kroese et al., Frontiers in Psychology, 5, 2014, 1). Two daily diary studies (N₁ = 185, N₂ = 137) investigated beliefs about willpower and stress as interactive predictors of bedtime procrastination. Beliefs about willpower capture whether people think of their willpower as limited resource that gets easily depleted (limited theory) or as something that remains regardless of previous acts of self-control (non-limited theory). Results show that after a stressful day, people with a limited versus non-limited theory procrastinate more on going to bed, while there is no difference in bedtime procrastination on less stressful days. Thus, ironically, limited theorists who should be more concerned with recovering their resources after a stressful day sleep less the following night.     

Effects of orthographic and phonological word length on memory for lists shown at RSVP and STM rates

This article reports 3 experiments in which effects of orthographic and phonological word length on memory were examined for short lists shown at rapid serial visual presentation (RSVP) and short-term memory (STM) rates. Only visual-orthographic length reduced RSVP serial recall, whereas both orthographic and phonological length lowered recall for STM lists in Experiment 1. Word-length effects may arise from output processes or from the temporal duration of output in recall. In 2 further experiments, output demands were reduced through the use of a recognition test. Recognition accuracy was impaired only by orthographic length for RSVP lists and by phonological length for STM lists in both experiments. The results demonstrate 2 item length effects not simply attributable to increased output time in recall, and implications for theories of STM are considered.     

When parallel processing in visual word recognition is not enough: new evidence from naming

Low-frequency irregular words are named more slowly and are more error prone than low-frequency regular words (the regularity effect). Rastle and Coltheart (1999) reported that this irregularity cost is modulated by the serial position of the irregular grapheme-phoneme correspondence, such that words with early irregularities exhibit a larger cost than words with late ones. They argued that these data implicate rule-based serial processing, and they also reported a successful simulation with a model that has a rule-based serial component—the DRC model of reading aloud (Coltheart, Rastle, Perry, Langdon, & Ziegler, 2001). However, Zorzi (2000) also simulated these data with a model that operates solely in parallel. Furthermore, Kwantes and Mewhort (1999) simulated these data with a serial processing model that has no rules for converting orthography to phonology. The human data reported by Rastle and Coltheart therefore neither require a serial processing account, nor successfully discriminate among a number of computational models of reading aloud. New data are presented wherein an interaction between the effects of regularity and serial position of irregularity is again reported for human readers. The DRC model simulated this interaction; no other implemented computational model does so. The present results are thus consistent with rule-based serial processing in reading aloud.     

Reading aloud: New evidence for contextual control over the breadth of lexical activation

Computational accounts of reading aloud largely ignore context when stipulating how processing unfolds. One exception to this state of affairs proposes adjusting the breadth of lexical knowledge in such models in response to differing contexts. Three experiments and corresponding simulations, using Coltheart, Rastle, Perry, Langdon, and Ziegler’s (2001) dual-route cascaded model, are reported. This work investigates a determinant of when a pseudohomophone such as brane is affected by the frequency of the word from which it is derived (e.g., the base word frequency of brain) by examining performance under conditions where it is read aloud faster than a nonword control such as frane. Reynolds and Besner’s (2005a) lexical breadth account makes the novel prediction that when a pseudohomophone advantage is seen, there will also be a base word frequency effect, provided exception words are also present. This prediction was confirmed. Five other accounts of this pattern of results are considered and found wanting. It is concluded that the lexical breadth account provides the most parsimonious account to date of these and related findings.     

Sensing sociality in dogs: what may make an interactive robot social?

This study investigated whether dogs would engage in social interactions with an unfamiliar robot, utilize the communicative signals it provides and to examine whether the level of sociality shown by the robot affects the dogs’ performance. We hypothesized that dogs would react to the communicative signals of a robot more successfully if the robot showed interactive social behaviour in general (towards both humans and dogs) than if it behaved in a machinelike, asocial way. The experiment consisted of an interactive phase followed by a pointing session, both with a human and a robotic experimenter. In the interaction phase, dogs witnessed a 6-min interaction episode between the owner and a human experimenter and another 6-min interaction episode between the owner and the robot. Each interaction episode was followed by the pointing phase in which the human/robot experimenter indicated the location of hidden food by using pointing gestures (two-way choice test). The results showed that in the interaction phase, the dogs’ behaviour towards the robot was affected by the differential exposure. Dogs spent more time staying near the robot experimenter as compared to the human experimenter, with this difference being even more pronounced when the robot behaved socially. Similarly, dogs spent more time gazing at the head of the robot experimenter when the situation was social. Dogs achieved a significantly lower level of performance (finding the hidden food) with the pointing robot than with the pointing human; however, separate analysis of the robot sessions suggested that gestures of the socially behaving robot were easier for the dogs to comprehend than gestures of the asocially behaving robot. Thus, the level of sociality shown by the robot was not enough to elicit the same set of social behaviours from the dogs as was possible with humans, although sociality had a positive effect on dog–robot interactions.     

Eudaimonic Orientation Enhances the Well-Being Experienced by Fathers

Applied Research in Quality of Life - The aim of this study was to investigate the potential moderating roles of eudaimonic orientation (prioritizing authenticity, meaning, excellence, growth) and...     

The Influence of Avoidance Temperament and Avoidance‐Based Achievement Goals on Flow

In the present research, we conducted two studies designed to examine the joint influence of avoidance temperament and avoidance‐based achievement goals on the experience of flow on a creativity task. In both a laboratory study (N = 101; M_age = 22.61, SD_age = 4.03; 74.3% female) and a naturalistic study (N = 102; M_age = 16.23, SD_age = 1.13; 48% female), participants high in avoidance temperament were shown to experience greater flow when performance‐avoidance goals were induced; no differences were found in any of the other three achievement goal conditions from the 2 × 2 achievement goal framework. These findings reveal a short‐term benefit for a disposition‐goal match grounded in avoidance motivation, and point to the need for more research on both avoidance‐based matches and the short‐term versus long‐term implications of such matches.