The independence of size perception and distance perception.

Research on distance perception has focused on environmental sources of information, which have been well documented; in contrast, size perception research has focused on familiarity or has relied on distance information. An analysis of these two parallel bodies of work reveals their lack of equivalence. Furthermore, definitions of familiarity need environmental grounding, specifically concerning the amount of size variation among different tokens of an object. To demonstrate the independence of size and distance perception, subjects in two experiments were asked to estimate the sizes of common objects from memory and then to estimate both the sizes and the distances of a subset of such objects displayed in front of them. The experiments found that token variation was a critical variable in the accuracy of size estimations, whether from memory or with vision, and that distance had no impact at all on size perception. Furthermore, when distance information was good, size had no effect on distance estimation; in contrast, at far distances, the distances to token variable or unknown objects were estimated with less accuracy. The results suggest that size perception has been misconceptualized, so that the relevant research to understand its properties has not been undertaken. The size-distance invariance hypothesis was shown to be inadequate for both areas of research.     

From handicap to handy capable: training systemic therapists in use of self

This article describes and discusses the rationale for an experiential methodology to help trainees expand their repertoire of behaviors in clinical situations. The goal in addressing the trainee's personal, "handicapping" responses is to pay attention to "how" a therapist is perceived, "why" a therapist has certain blindspots, and "what" the therapist does to co-create a therapeutic impasse. In addition, experientially considering the impact of self encourages therapists to "learn to learn" that they are an active, resourceful participant in the evolutionary process of the therapeutic system.     

Reaction time to letter name or letter case

Subjects were shown two letters from the set BDGbdg. In one condition, subjects were required to decide whether or not the letters had the same name. In the other condition, subjects decided whether or not the two letters were presented in the same case. Reaction times were always faster when the two letters on a given trial were physically identical. However, there was no difference in the speed of a name match or a case match when the two letters were not physically identical. Since subjects could have based a case match on the presence or absence of a single feature — a protruding vertical line — it was concluded that subjects are not able to selectively attend to a single visual feature in order to identify a letter. Rather, a subject analyzes several features in parallel in order to arrive at a simultaneous decision about a letter's name or case.     

Mechanisms of aural encoding: VIII. Phonetic interference and context-sensitive coding in short-term memory

In previous experiments Ss were presented for ordered recall with sequences of five consonant phonemes paired with /a/ in which the middle three consonant phonemes shared the same manner of articulation (voiced, unvoiced, nasal), the same place of articulation (front, middle, back), or neither the same manner nor place of articulation (control sequences). Compared to performance in control sequences, the middle consonant phoneme was always more difficult to recall in manner of articulation sequences but not in place of articulation sequences. The results suggested that for these sequences consonant phonemes were not remembered in terms of their place of articulation. In the present experiment, sequences of consonant-vowel (CV) or vowel-consonant (VC) syllables were presented for recall in which each consonant phoneme was paired with a different vowel. When consonant phonemes in the different sequence types were presented for recall with different vowels, phonetic interference was observed for the middle consonant in place of articulation sequences as well as manner of articulation sequences, and the effect was observed in both CV and VC groups. It was suggested that vowels are encoded in short-term memory in terms of their place of articulation and that presenting consonant phonemes for recall with different vowels caused Ss to use this dimension to code consonant phonemes in short-term memory.     

Sequential letter and word recognition in deaf and hearing subjects

To examine the processing of sequentially presented letters of familiar and nonsense words, especially among Ss of vastly differing experience on sequential tasks, three groups of Ss were tested on letters of words spelled sequentially on an alphanumeric display and on letters of words fingerspelled. These were a deaf group (N=33) with little or no hearing and who varied in their fingerspelling ability; a staff group (N=12) who taught fingerspelling and were highly proficient; and a hearing group (N=19). Of principal interest was the finding that the hearing Ss did better on nonsense letter recognition, while the deaf group did better on word recognition. Word length was important except to the staff Ss on fingerspelled words, which also suggests that concentration on fingerspelling proficiency forces attention to the whole word and not its component letters. Hearing Ss, who are the group faced with an unfamiliar task, seemed to attend to each letter and hence had more difficulty with recognition of the longer unit.     

Mechanisms of aural encoding: I. Distinctive features for consonants

To examine the importance of distinctive features that are used to encode consonants (following Wickelgren’s analysis) in an immediate recall task, sequences of 5 consonants, all paired with the vowel /a/ were constructed and presented aurally for recall. The middle three items in each sequence all had either the same place of articulation (front, middle, or back of the vocal apparatus), orthe same manner of articulation (voiced, unvoiced, or nasal), or were unrelated in either place or manner (control). It was shown that, in comparison with the control sequences, consonants imbedded among others articulated similarly were recalled less accurately, suggesting that these distinctive features are important in encoding and memory maintenance. A comparison of the 3 manner and 3 place features showed that the greatest difficulty in recall occurred for the similar manner sequences (especially voiced and unvoiced, implicating manner of articulation as the critical distinctive feature in aural encoding. Some discussion is also presented of a distinction between articulation and acoustic factors in encoding processes.     

A replication and extension of the Eriksen and Steffy (1964) experiment on short-term visual storage

Eriksen and Steffy (1964) were critical of short-term visual storage effects (STVS) because they were unable to find any evidence for them. In their first experiment they found instead great interference in performance over the same ISIs in which STVS is usually found. Their second experiment eliminated the interference by avoiding a bright second flash, but it still produced no evidence for STVS. Keele and Chase (1967) demonstrated that Eriksen and Steffy’s second condition failed to find STVS because the memory load was too small, and perhaps because the luminance was too low. However, the design of Eriksen and Steffy’s second experiment is not the one typically used to find STVS. Eriksen and Steffy’s first experiment was replicated here, and a second condition was added in which each S was also tested in a light adapted version. Interference was found in the former, as Eriksen and Steffy also found, but not in the latter. Little STVS was found in either of these conditions, presumably for reasons similar to those demonstrated by Keele and Chase.     

How much help do repeated presentations give to recognition processes?

A recent experiment by Haber and Hershenson (1965) had shown that in a recognition task one long look at a stimulus was always superior to two or more shorter looks summing to the same total presentation time. In order to explore this more fully and to account for opposite results in a different type of recognition task, as well as in a serial learning task, an improved replication of the earlier study was carried out using very short durations and single letters as stimuli. The same non-reciprocity was found, again strongly favoring duration over repetition as a determinant of clarity of a percept, even though repetition alone was also shown to be a significant independent variable. As a subsidiary finding, an error analysis showed that when a letter was misnamed it was nearly always confused with one that looked like it rather than one that sounded like it. Some discussion was offered as to the role of an auditory information storage in low memory load tasks such as this one, as well as some general implications for information processing analyses of the non-reciprocity of duration and repetition.