The perception of /r/ and /l/ in syllable-initial and syllable-final position

American English liquids /r/ and /l/ have been considered intermediate between stop consonants and vowels acoustically, articulatorily, phonologically, and perceptually. Cutting (1947a) found position-dependent ear advantages for liquids in a dichotic listening task: syllable-initial liquids produced significant right ear advantages, while syllable-final liquids produced no reliable ear advantages. The present study employed identification and discrimination tasks to determine whether /r/and /l/ are perceived differently depending on syllable position when perception is tested by a different method. Fifteen subjects listened to two synthetically produced speech series—/li/ to /ri/ and /il/ to /ir/—in which stepwise variations of the third formant cued the difference in consonant identity. The results indicated that: (1) perception did not differ between syllable positions (in contrast to the dichotic listening results), (2) liquids in both syllable positions were perceived categorically, and (3) discrimination of a nonspeech control series did not account for the perception of the speech sounds.     

NEURAL EXCITATION AND SUSTAINED SINUSOIDAL ACOUSTIC STIMULATION

On the basis of equal-loudness contours expressed in terms of volume velocity of cochlear fluid, a theory is developed for equal loudness at high levels of stimulation. At these levels the theory assumes number of active nerve fibers to be proportional to volume velocity of cochlear fluid, and firing rate of fibers to be limited by the refractory period. Analysis of a set of threshold data seemed to confirm these assumptions, and was in disagreement with the notion of power summation at the absolute threshold.     

Event plausibility does not determine children's false memories

In this paper we ask how the plausibility of an event affects the likelihood that children will develop a false memory for it. Over three interviews 6-year-olds and 10-year-olds were shown two true photos and two false photos—a plausible and less plausible event—and reported what they could remember about those events. Children also rated their confidence that the events happened, and how much they could remember about the events. By the final interview, within each age group, there were no differences in children's confidence ratings for the two false events. In addition, within each age group, the rate of false memories was the same for each event; across age groups, younger children developed more false memories than older children.     

Source confusion influences the effectiveness of the autobiographical IAT

We examined the claim that the autobiographical Implicit Association Test (aIAT) can detect concealed memories. Subjects read action statements (e.g., “break the toothpick”) and either performed the action or completed math problems. They then imagined some of these actions and some new actions. Two weeks later, the subjects completed a memory test and then an aIAT in which they categorized true and false statements (e.g., “I am in front of the computer”) and whether they had or had not performed actions from Session 1. For half of the subjects, the nonperformed statements were actions that they saw but did not perform; for the remaining subjects, these statements were actions that they saw and imagined but did not perform. Our results showed that the aIAT can distinguish between true autobiographical events (performed actions) and false events (nonperformed actions), but that it is less effective, the more that subjects remember performing actions that they did not really perform. Thus, the diagnosticity of the aIAT may be limited.     

Investigating the variability of memory distortion for an analogue trauma

In this paper, we examine whether source monitoring (SM) errors might be one mechanism that accounts for traumatic memory distortion. Participants watched a traumatic film with some critical (crux) and non-critical (non-crux) scenes removed. Twenty-four hours later, they completed a memory test. To increase the likelihood participants would notice the film's gaps, we inserted visual static for the length of each missing scene. We then added manipulations designed to affect people's SM behaviour. To encourage systematic SM, before watching the film, we warned half the participants that we had removed some scenes. To encourage heuristic SM some participants also saw labels describing the missing scenes. Adding static highlighting, the missing scenes did not affect false recognition of those missing scenes. However, a warning decreased, while labels increased, participants' false recognition rates. We conclude that manipulations designed to affect SM behaviour also affect the degree of memory distortion in our paradigm.     

A few seemingly harmless routes to a false memory

Since the invention of photography we have learned to rely on photos to help us remember significant moments in our lives. We have come to believe that photographs are accurate and valuable records of events that—years down the track—we may not be able to remember. In this paper, we review recent research demonstrating that photographs can also help us to “remember” events that never really happened. We trace the development of the leading false autobiographical memory paradigm, and we then describe research on the power of both fake narrative stories and fake photographs to cultivate false memories.     

Perception of dynamic information for vowels in syllable onsets and offsets

It has been demonstrated using the “silent-center” (SC) syllable paradigm that there is sufficient information in syllable onsets and offsets,taken together, to support accurate identification of vowels spoken in both citation-form syllables and syllables spoken in sentence context. Using edited natural speech stimuli, the present study examined the identification of American English vowels when increasing amounts of syllable onsetsalone or syllable offsetsalone were presented in their original sentence context. The stimuli were /d/-vowel-/d/ syllables spoken in a short carrier sentence by a male speaker. Listeners attempted to identify the vowels in experimental conditions that differed in the number of pitch periods presented and whether the pitch periods were from syllable onsets or syllable off-sets. In general, syllable onsets were more informative than syllable offsets, although neither onsets nor offsets alone specified vowel identity as well as onsets and offsets together (SC syllables). Vowels differed widely in ease of identification; the diphthongized long vowels /e/, /ae/, /o/ were especially difficult to identify from syllable offsets. Identification of vowels as “front” or “back” was accurate, even from short samples of the syllable; however, vowel "height" was quite difficult to determine, again, especially from syllable offsets. The results emphasize the perceptual importance of time-varying acoustic parameters, which are the direct consequence of the articulatory dynamics involved in producing syllables.