1. Inference to Best Explanation Example: Baddeley & Hitch model of working memory This model contains modules for the Central Executive and Assistant Processes. One Assistant Process is the phonological loop (involving subvocal speech, spoken speech, and a phonological buffer/store).

2. To create the model, researchers have considered: 1. CAPACITY HOW? By looking at letter span measurement RESULT: Limited capacity – about 7-8 letters in English 2. NATURE OF PROCESSING HOW? By evaluating specific types of errors RESULT: Substitutions are made with letters that sound the same even when letters are presented visually INFERENCE: Working memory is limited in how many letter names can be held temporarily INFERENCE: The letters are coded in verbal form

3. 3. RELATIONSHIP OF THE PHONOLOGICAL BUFFER CAPACITY TO VARIOUS TASKS HOW? Use concurrent vocalization (e.g., “tah, tah, tah”) when letters are presented visually RESULTS: 1. Reduces letter span 2. Has no negative effect on problem solving 3. Has no negative effect on memory for complex visual shapes INFERENCES: Letter span typically involves mechanisms used for subvocal speech but also for overt speech. Such processes are not involved in problem solving or visual shape memory.

4. 4. THE ROLE OF SPEECH MUSCLES HOW? Look at subvocalization effects on letter span in individuals who are unable to use muscles involved in speech RESULT: These individuals show the same effects of subvocalization on letter span INFERENCE: Subvocal speech does not involve the use of speech muscles

5. The articulatory rehearsal loop involves 2 components—subvocal speech and a phonological buffer. Subvocalization loads the buffer. At the same time, the central executive can work on other matters, until it then has to read the buffer to prevent decay. Items can pass through this process multiple times.

6. Mechanisms used for actual speech overlap with those for subvocal speech and are not available for subvocal rehearsal if participants are saying “tah-tah-tah”, etc., out loud.