Eyes wide open: Pupil size as a proxy for inhibition in the masked-priming paradigm.

A core assumption underlying competitive-network models of word recognition is that in order for a word to be recognized, the representations of competing orthographically similar words must be inhibited. This inhibitory mechanism is revealed in the masked-priming lexical-decision task (LDT) when responses to orthographically similar word prime-target pairs are slower than orthographically different word prime-target pairs (i.e., inhibitory priming). In English, however, behavioral evidence for inhibitory priming has been mixed. In the present study, we utilized a physiological correlate of cognitive effort never before used in the masked-priming LDT, pupil size, to replicate and extend behavioral demonstrations of inhibitory effects (i.e., Nakayama, Sears, & Lupker, Journal of Experimental Psychology: Human Perception and Performance, 34, 1236-1260, 2008, Exp. 1). Previous research had suggested that pupil size is a reliable indicator of cognitive load, making it a promising index of lexical inhibition. Our pupillometric data replicated and extended previous behavioral findings, in that inhibition was obtained for orthographically similar word prime-target pairs. However, our response time data provided only a partial replication of Nakayama et al. Journal of Experimental Psychology: Human Perception and Performance, 34, 1236-1260, 2008. These results provide converging lines of evidence that inhibition operates in word recognition and that pupillometry is a useful addition to word recognition researchers' toolbox.

Orthographic similarity: the case of "reversed anagrams".

How orthographically similar are words such as paws and swap, flow and wolf, or live and evil? According to the letter position coding schemes used in models of visual word recognition, these reversed anagrams are considered to be less similar than words that share letters in the same absolute or relative positions (such as home and hose or plan and lane). Therefore, reversed anagrams should not produce the standard orthographic similarity effects found using substitution neighbors (e.g., home, hose). Simulations using the spatial coding model (Davis, Psychological Review 117, 713-758, 2010), for example, predict an inhibitory masked-priming effect for substitution neighbor word pairs but a null effect for reversed anagrams. Nevertheless, we obtained significant inhibitory priming using both stimulus types (Experiment 1). We also demonstrated that robust repetition blindness can be obtained for reversed anagrams (Experiment 2). Reversed anagrams therefore provide a new test for models of visual word recognition and orthographic similarity.

Repetition blindness: an emergent property of inter-item competition.

Repeating an item in a brief or rapid display usually produces faster or more accurate identification of the item (repetition priming), but sometimes produces the opposite effect (repetition blindness). We present a theory of short-term repetition effects, the competition hypothesis, which explains these paradoxical outcomes. The central tenet of the theory is that repetition produces a representation with a higher signal-to-noise ratio but also produces a disadvantage in the representation's ability to compete with other items for access to awareness. A computational implementation of the competition hypothesis was developed to simulate standard findings in the RB literature and to generate novel predictions which were then tested in three experiments. Results from these experiments suggest that repetition effects emerge from competitive interactions between items and that these influences extend to adjacent, nonrepeated items in the display. The results also present challenges to existing theories of short-term repetition effects.

Fast pairs: a visual word recognition paradigm for measuring entrenchment, top-down effects, and subjective phenomenology.

When word pairs having a familiar order are sequentially flashed on a computer in their non-familiar order, (code zip), observers have a strong phenomenology of seeing them in familiar order (zip code). Reversal errors remained frequent even when participants obtained perceptual experience of reverse-display items by beginning with a block of longer-duration trials. A forced-choice order-detection procedure reduced but did not eliminate reversal errors, showing that "fast pairs" is a robust perceptual illusion. Even adjective + noun pairs (green skirt) showed reversal errors, and reversal errors increased with the log frequency of the word pair, consistent with a strong role for statistical processing at the level of multi-word units.

The role of autonomic arousal in feelings of familiarity.

Subjective feelings of familiarity associated with a stimulus tend to be strongest when specific information about the previous encounter with the stimulus is difficult to retrieve (e.g., the butcher-on-the-bus phenomenon; [Mandler, G. (1980). Recognizing: The judgment of previous occurrence. Psychological Review, 87, 252-271.]). When a stimulus has been encountered previously and the circumstances of the encounter cannot be recollected, additional cognitive resources may be directed toward recollection processes; this resource allocation is accompanied by autonomic arousal [Dawson, M. E., Filion, D. L., & Schell, A. M. (1989). Is elicitation of the autonomic orienting response associated with allocation of processing resources?. Psychophysiology, 26, 560-572]. One easily measurable index of autonomic arousal is the skin conductance response (SCR). In the present study, participants studied lists of words and then gave recognition ratings to briefly displayed and masked studied and nonstudied test words while their SCRs were monitored. Results revealed a relationship between recognition ratings and the temporal characteristics of the SCR, supporting the idea that feelings of familiarity are indeed "feelings" in that they stem from autonomic arousal associated with cognitive resource allocation.

Now you see it, now you don't: repetition blindness for nonwords.

Repetition blindness (RB) for nonwords has been found in some studies, but not in others. The authors propose that the discrepancy in results is fueled by participant strategy; specifically, when rapid serial visual presentation lists are short and participants are explicitly informed that some trials will contain repetitions, participants are able to use partial orthographic information to correctly guess repetitions on repetition trials while avoiding spurious repetition reports on control trials. The authors first replicated V. Coltheart and R. Langdon's (2003) finding of RB for words but repetition advantage for nonwords (Experiment 1). When all participants were encouraged to utilize partial information in a same/different matching task along with an identification task, a repetition advantage was observed for both words and nonwords (Experiment 2). When guessing of repetitions was made detectable by including non-identical but orthographically similar items in the experiments, the repetition advantage disappeared; instead, RB was found for both words and nonwords (Experiments 3 and 4). Finally, when experiments did not contain any identical items, participants almost never reported repetitions, and reliable RB was found for orthographically similar words and nonwords (Experiments 5 and 6).

Semantic interference and associative facilitation from words presented in rapid serial visual presentation.

Semantic interference in picture naming is readily obtained when categorically related distractor words are displayed with picture targets; however, this is not typically the case when both primes and targets are words. Researchers have argued that to obtain semantic interference for word primes and targets, the prime must be shown for a sufficient duration, prime processing must be made difficult, and participants must attend to the primes. In this article, we used a novel procedure for prime presentation to investigate semantic interference in word naming. Primes were presented as the last word of a rapid serial visual presentation stream, with the target following 600-1,200 msec later. Semantic interference was observed for categorically related targets, whereas facilitation was found for associatively related targets.

Recognition memory for novel stimuli: the structural regularity hypothesis.

Early studies of human memory suggest that adherence to a known structural regularity (e.g., orthographic regularity) benefits memory for an otherwise novel stimulus (e.g., G. A. Miller, 1958). However, a more recent study suggests that structural regularity can lead to an increase in false-positive responses on recognition memory tests (B. W. A. Whittlesea & L. D. Williams, 1998). In the present study the authors attempted to identify the circumstances under which structural regularity benefits old-new discrimination and those under which it leads to an increase in false-positive responses. The highly generalizable tendency shown here is for structural regularity to benefit old-new discrimination. The increase in false-positive responses for structurally regular novel items may be limited to situations in which regularity is confounded with similarity to studied items.

Repetition blindness: out of sight or out of mind?

Does repetition blindness represent a failure of perception or of memory? In Experiment 1, participants viewed rapid serial visual presentation (RSVP) sentences. When critical words (C1 and C2) were orthographically similar, C2 was frequently omitted from serial report; however, repetition priming for C2 on a postsentence lexical decision task was equivalent whether or not C1 was similar to C2. In Experiment 2, participants monitored RSVP sentences for a predetermined target. Participants frequently failed to detect the target when it was preceded by an orthographically similar word. In Experiment 3, the authors investigated the role of the attentional blink in this effect. These experiments suggest that repetition blindness is a failure of conscious perception, consistent with predictions of the token-individuation hypothesis.

Repetition blindness occurs in nonwords.

Theorists have predicted that repetition blindness (RB) should be absent for nonwords because they do not activate preexisting mental types. The authors hypothesized that RB would be observed for nonwords because RB can occur at a sublexical level. Four experiments showed that RB is observed for word-nonword pairs (noon noof), orthographically similar nonwords (glome glame), and identical repetitions (plass plass). More RB was found for words than for nonwords. Prior researchers may have failed to find RB for nonwords because display conditions that allow 2 words to be reliably encoded are insufficient for nonwords, or because observers coped with low ability to encode nonwords by using guessing strategies that do not require creating a mental type or tokenizing it.

Sentence context, word recognition, and repetition blindness.

When the sentence She ran her best time yet in the rice last week is displayed using rapid serial visual presentation, viewers sometimes misread rice as race (M. C. Potter, A. Moryadas, I. Abrams, & A. Noel, 1993). Seven experiments combined misreading and repetition blindness (RB) paradigms to determine whether misreading of a word because of biasing sentence context represents a genuine perceptual effect. In Experiments 1-4, misreading a word either caused or prevented RB for a downstream word, depending on whether orthographic similarity was increased or decreased. Additional experiments examined temporal parameters of misreading RB and tested the hypothesis that RB results from reconstructive memory processes. Results suggest that the effect of prior context occurs during perception.