Kathryn T. Spoehr

The role of syllables in perceptual processing

Abstract Three experiments examined tachistoscopic reports for numbers and words as a function of the number of syllables in the item. Experiment I showed that the number of syllables in the vocalization of a two-digit number had no effect on report accuracy, indicating that tachistoscopic accuracy is unaffected by the duration of any implicit speech process. Experiment II showed that tachistoscopic accuracy was greater for one- than for two-syllable words, and it was hypothesized that this difference was due to the syllable functioning as a single perceptual unit. Subsequent probability analyses indicated that one-syllable words were indeed processed in a more unitary manner than two-syllable words, but suggested that the critical perceptual unit was a vocalic center group (Hansen & Rodgers, 1965) rather than a syllable. Experiment III further indicated that the difference between one- and two-syllable words was a perceptual one. The results were discussed in terms of processing stage models of word perception.

The role of orthographic and phonotactic rules in perceiving letter patterns.

Three experiments examined the role of orthographic and phonotactic rules in the tachistoscopic recognition of letter strings. Experiment 1 showed that the presence of a vowel or multiletter spelling patterns facilitates perceptual accuracy. To account for these results a model was proposed in which an input string is first parsed into syllablelike units, which are then recorded into speech. It was demonstrated that the perceptual accuracy for a string is correlated with the number of recoding steps needed to convert that string into speech. Experiment 2 further demonstrated that this recoding process can predict perceptibility differences among strings with varying numbers of phonotactic violations, and Experiment 3 assessed some of the specific assumptions of the recoding process.

The stimulus suffix effect as a memory coding phenomenon

Two short-term memory experiments examined the nature of the stimulus suffix effect on auditory linguistic and nonlinguistic stimulus lists. In Experiment 1, where subjects recalled eight-item digit lists, it was found that a silently articulated digit suffix had the same effect on recall for the last list item as a spoken digit suffix. In Experiment 2, subjects recalled lists of sounds made by inanimate objects either by listing the names of the objects or by ordering a set of drawings of the objects. Auditory suffixes, either another object sound or the spoken name of an object, produced a suffix effect under both recall conditions, but a visually presented picture also produced a suffix effect when subjects recalled using pictures. The results were most adequately explained by a levels-of-processing memory coding hypothesis.

Visual information processing

What is visual information processing? There are a large number of identifiable visual processing skills operating within the visual system. There are different systems to describe these functions. One approach is to divide visual information processing into the following functions: visual cognition, visual memory, pattern recognition, scanning and visual attention. These functions can be described as follows 1 : Visual cognition: The ability to mentally manipulate visual information and integrate it with other sensory information to solve problems, formulate plans and make decisions. It includes the ability to analyze similarities and differences, to understand the relationship of stimulus elements to one another, and to reason and deduce about the nature of visual stimuli. It also includes the ability to use contextual cues to help in the development of meaning from the image. Visual memory: The ability to visually process stimuli, store them in memory and retrieve them upon command. The individual must also be able to match what they see with what is stored in memory. Pattern recognition: The ability to identify the salient features of an object including configural and holistic aspects such a shape, contour, and general features, such as color, details, shading, and texture. It is important for the individual to be able to recognize objects even when viewed from different or obscure angles (perceptual constancy). Scanning: The ability to record all details of a scene systematically in an organized and thorough manner. The route taken is known as the scan path. The eyes obtain and process information by executing a series of broad sweeping cycles with reexamination of the most important details several times to ensure identification. These eye movements are called saccades. Saccadic eye movements are normally executed in an organized, systematic, and efficient pattern. Visual attention: The ability to attend to stimuli and shift attention between stimuli. How are visual information processing deficits treated? Due to a brain injury or organic causes an individual may have deficits in one or more components of visual information processing. The best illustration of vision therapy in the treatment of visual processing disorders comes in patients with brain injuries, as the presence of an injured brain makes treatment more challenging. Vision therapy or training has been shown to successfully treat visual processing deficits even in the presence of brain injuries. A number of studies taken from neurological, optometric and occupational therapeutic literature show the effect of visual processing …

Effects of stimulus and contextual information on the lexical decision process

Two experiments were conducted to investigate context effects on the lexical decision process. In both experiments, observers classified letter strings as words or nonwords following the presentation of context in the form of an incomplete sentence. In Experiment 1, the predictability of congruous word stimuli and their frequency of occurrence in printed English were varied. These two factors had independent and additive effects on decision latencies. Stimulus quality, word frequency, and semantic congruity (i.e., congruous vs. incongruous) between the context and the stimulus were varied in Experiment 2. The effects of semantic congruity and word frequency on decision latencies combined additively, as did the effects of semantic congruity and stimulus quality. Two complementary mechanisms were proposed within the framework of a modified version of Becker’s verification model to account for the differential effects of single-word and sentence context priming on the lexical decision process.

The direct measurement of hypothesis-sampling strategies ☆

Abstract The concept-identification (CI) literature supports a hypothesis-sampling theory. Hypotheses based on attributes, sample sizes greater than one, and nonreplacement of eliminated hypotheses all occur. An experimental procedure was developed to measure hypothesis-sampling directly where the subject is allowed to select attributes that he wishes to see, then randomly selected values on the selected attributes are presented. Generally, the average sample size before the trial of the last error (TLE) does not change but does change after TLE. The probabilities of eliminating inconsistent hypotheses and keeping consistent hypotheses increase over problems. The proportion of eliminated attributes which are resampled decreases over problems. Individual subjects are extremely varied in sample size, efficiency measures, and resampling tendencies. The rate of solution, TLE, is related to the efficiency and resampling measures but not to the sample size.

Conceptual Models for Understanding the Behavior of Electrical Circuits

We are investigating the role that computer-based models can play in helping students to learn science. In the research reported in this chapter, we conducted experimental trials of a computer environment that provides linked models that represent circuit behavior from different perspectives (such as a microscopic versus a macroscopic perspective) and at differing levels of abstraction. In these trials, we varied the number of linked causal models that were given to different groups of students. Our objective was to determine whether working with reductionistic models (a) reduces students’ misconceptions, particularly their adherence to the commonly held “current-as-agent” misconception, and (b) increases the robustness and flexibility of students’ knowledge as they solve circuit problems and explain circuit phenomena. The first model that we developed and utilized, called the “particle model,” illustrates the behavior of mobile, charged particles within a conductive medium and their changes in position over time. The basic interaction among particles within this model is the Coulomb interaction (like charges repel, unlike charges attract). A second model that we developed depicts — at a higher level of abstraction — the properties of a system that incorporates such a mechanism. This model, called the “transport model,” incorporates more abstract representations of voltage and charge flow. The particle model can be used to provide an explanation or “unpacking” for processes that are considered primitives within the transport model. We conducted an experiment that examined students’ performance on a variety of circuit problems before and after they learned either (a) the transport model alone, or (b) the transport model augmented with explanations of its processes in terms of the particle model. We then compared performance on problems for which a current-as-agent conception is sufficient with performance on problems that require a full understanding of how voltages are created and distributed within a circuit. The posttest results revealed that both groups achieved a high level of performance on a wide range of problems. However, the subjects who received a particle model explanation for the basic concepts and processes of the transport model achieved a higher level of performance than the other group on problems that require an understanding of voltage and charge distribution. We conjecture that this is due to the particle model explanations providing students with a mechanistic model for voltage and charge distribution that is consistent with the behavior of the transport model and that inhibits the construction and use of the current-as-agent misconception.

Mental multiplication: Nothing but the facts?

Current models of adult arithmetic performance assume that representation includes only facts and procedures. However, other kinds of representations such as an analog scale or sets of number multiples might be useful in a variety of multiplication-related tasks. Introducing the practice transfer paradigm, we demonstrate that associations between distinct representational structures can be detected via cross-task transfer, provided that initial performance is retrieval based. Results support the predictions of the integrated-structures model of multiplication knowledge. Implications for well-established item differences such as the problem-size effect are addressed, and the question of how integration occurs is considered.

Solving anagrams: Category priming and the differential availability of category solutions

An experiment was performed to test the hypothesis that the effect of category name priming on anagram solving varies with the strength of the relationship between the solution word and the priming category. Subjects solved anagrams of taxonomic category instances under primed or unprimed conditions. In the primed condition, the name of the taxonomic category from which the solution word was chosen was provided on each trial. Priming was shown to facilitate anagram solution and the extent of this facilitation was directly related to the instance dominance of the solution word in the priming category. The results were discussed in terms of current models of semantic memory.

The suffix effect: Postcategorical attributes in a serial recall paradigm

A serial list learning paradigm was employed to investigate the role of postcategorical information in producing the stimulus suffix effect (SSE). Serial recall performance was measured for eight-item word lists under four experimental conditions: a control condition (C), where white noise was used as a stimulus suffix; the word-suffix (WS) condition, where list items and suffix were semantically unrelated; the target-suffix condition (TS), in which the final list item and the suffix were from the same category; and the category-suffix condition, in which the final three list elements and the suffix were from the same category. All three verbal suffix conditions produced the SSE, but its magnitude was reduced when the suffix was semantically related to the last list element. Several pre- and postcategorical explanations of the SSE are evaluated in light of the results.