Practical 2

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Practical 2

• Writing up the method

2
Class Activity

• As we go through the points examine your report
  and make the necessary corrections.
• Dont be too shy to stop and ask us if you have a
  query

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Feedback (1) Title general

• Important words/ the practical was about simple
  reaction time impact of auditory or visual
  stimuli -
• Irrelevant/vague parts research on, an
  exploration of ?
• Scientific approach The current study vs In
  my experiment or I carried out an expt/
• Good parts you split the report up wellit was
  not too wordy, included results

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Feedback (2) Table

• Labelling and title Need to have - Table 1,
  table 2, good description above the table
• Sample size N often omitted.
• Good points nicely word processed, and layout
  fine.
• Be consistent with decimal points - 2 is enough
• Do not copy our tables or figures too closely we
  would like to see some of your contribution

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Feedback (2b) Figure

• Labelling and title Need to have - Figure 1,
  good description label is at the bottom
• Axes labelled properly reaction time msecs vs
  modality of stimulus
• Axes labelled properly results of experiment
  too vague
• Do not copy our figures

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Feedback (3) Comment

• Irrelevant material a few people included too
  much method, or discussion of theories,
• Hypotheses- need to say whether supported.
• Good points usually the tables referred to
  correctly
• Decide whether to use means of means or medians -
  One was better, could say why and then simple
  use in reduced tables.
• Reaction time - bigger the number, slower
  reaction

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Feedback (4) Other points

• Have a logical structure - dont say what the
  outcome was before you have described the data
  for the reader
• Language and style - not too bad, remember be
  concise scientific!

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Learning Outcomes 1

• Carry out a typical piece of laboratory research
  in psychology.
• Use a within subjects design (Repeated measures )
  factors and comment on the strengths and
  weaknesses of the design
• Distinguish independent and dependent variables
• Understand the importance of random allocation of
  subjects and counterbalancing

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Learning Outcomes 2

• Understand the importance of randomisation of
  materials
• Summarise results into a table
• Write up a report including a Title, Method,
  Results

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Experimental issues to consider

• Within subjects design (the same participant
  participates in every condition)

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Experimental issues to consider

• Within subjects design (the same participant
  participates in every condition)
• Advantages fewer subjects and less variability
  in subjects
• Disadvantages learning, order, sequence effects.
•  
• Controlling for order effects
•   Counterbalancing (varying the order in which
  the participants experience the conditions)
• Randomize trials within a block

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What will happen

• Get into pairs
• Experiment will involve determining a recognition
  threshold
• Some notes on Fechner to follow
• Participants leave the room while instructions
  are explained to experimenters

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Gustav Theodor Fechner 1801-1887

• German experimental psychologist.

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Gustav Theodor Fechner (April 19, 1801 November
28, 1887)

• Born at Gross-Särchen, near Muskau, in Lower
  Lusatia. Educated at Sorau and Dresden and at the
  University of Leipzig. In 1834 he was appointed
  professor of physics, but in 1839 contracted an
  eye disorder while studying the phenomena of
  colour and vision, and, after much suffering,
  resigned. Subsequently recovering, he turned to
  the study of the mind and its relations with the
  body.

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Fechner Elemente der Psychophysik 1860

• Bodily facts and conscious facts are different
  sides of one reality.
• Tried to discover an exact mathematical relation
  between them.
• Weber's Fechner's law
• "In order that the intensity of a sensation may
  increase in arithmetical progression, the
  stimulus must increase in geometrical
  progression."

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Threshold measurement

• Thresholds interesting since are measuring the
  relationship between a psychological property,
  sensation, and changes in physical objects
• the research field of thresholds is known as
  psychophysics

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Threshold (limen) measurement

• Different techniques were used to measure
  thresholds.
• In today's experiment we will try to determine a
  threshold, so that the participant is working
  near to their limits of performance.
• The method used will start below the threshold
  and then increase presentation time until the
  stimulus is recognised.

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lateralisation

• http//psych.unn.ac.uk/ then webspace server,
  then practical 2 program
• make browser take up more of screen, F11

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Pause to run research

• Do research.
• Decide on a rep for each lab group over the
  break
• Think about research participation

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Before and after break

• Submit results,
• No. of 1 2 accurately reported
• no. words left and no. words right
• exposure duration
• whether person left or right handed

Before
After
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3 theories

• Reading habits

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3 theories

• Guessing

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3 theories

• Functional differences between brain hemispheres
  (favoured explanation)

• See also results of sectioning corpus callosum.
• Work of Sperry,
• Gazziniga

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Brain lateralisation

• Brain is a Paired organ
• Corpus callosum
• Different functions for each hemisphere?
• Left Visual Field Right Visual Field
• Left Hemisphere Right Hemisphere
• http//psych.unn.ac.uk/java/lateral.html

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Dr Mises or Fechner

• As Dr Mises, Fechner wrote a comparative anatomy
  of angels - angels are perfect, a sphere is
  perfect, angels must be spheres.
• Proof that the moon was made of iodine
• at same time discovered psychophysics
• Was psychophysics a joke like his Dr Mises work?

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Method section

• See handbook examples
• We want you to include a design subsection and
  describe the independent and dependent variables
• Also need participants, apparatus and procedure
• We want a results section
• Heffernan A students guide to studying
  psychology.

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Design

• Design
• There were five experimental conditions for each
  group of participants. The conditions were
  identical for each group except that one group
  had as their primary task retention of the matrix
  locations, while the other group performed the
  nonsense version of the task. The conditions were
  as follows Brooks matrix/verbal performed alone,
  random number generation performed alone,
  matrix/verbal task with articulatory suppression,
  matrix/verbal task with spatial suppression, and
  matrix/verbal task with random number generation.
  The order of the five conditions was
  counterbalanced across participants except that
  the two single task conditions occurred only in
  positions two and four in the order for
  participants. The tasks were performed in
  sequence until the participant had performed each
  task three times. In the case of the matrix and
  verbal tasks, on each occasion participants were
  given five lists. Therefore data were collected
  for each of these tasks from a total of 15 lists
  in the control single task condition, and 15
  lists in each of the three dual task conditions
  giving a total of 60 lists in all.

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Design

• What is the experimental design of this study?
• What was the Independent Variable(s)?
• What was the Dependent Variable?
• How were Carry-over effects controlled?

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Participants

• Participants
• Participants were 18 females and 30 males
  recruited from the psychology department
  participant panel, with a mean age of 29 years
  (SD 10 years). These were a mixture of
  undergraduate students and members of the general
  public. All were given a small honorarium for
  taking part. Participants were randomly split
  into two groups, with 24 participants (nine
  females and 15 males) performing the Brooks
  matrix task, and the other 24 participants (nine
  females and 15 males) performing the Brooks
  nonsense task.

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Participants

• How many?
• What details of the participants are important in
  this study?
• Were they volunteers, paid, course requirement?

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Materials/Apparatus

• An letter adaptation of the Brooks (1967) matrix
  task was employed (see Appendix 1) as the visual
  task, and the Brooks (1967), verbal (nonsense)
  task was adapted using letters as for the matrix
  task (Appendix 2). The secondary tasks used were
  articulatory suppression, spatial suppression and
  random generation. See Appendix 3 for further
  details.

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Materials/Apparatus

• Is the computer type and monitor important?
• How was it programmed?
• What sort of words were used?

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Procedure

• Participants were tested individually and the
  session started with an instruction and practice
  period of about 30 minutes. All of the tasks were
  explained verbally, and in the case of random
  generation, with written instructions. The
  participant was first given practice with five
  lists on the matrix or verbal task. These lists
  were different from those used in the main
  experiment. The participant then read the
  instructions for random number generation, and
  practised the task for 100 s in time with the
  metronome. Next the articulatory suppression
  procedure was explained and practised by the
  participant for 20 s in time with the metronome.
  The procedure for the spatial suppression task
  was similarly explained and practised for 20 s.
  Next, participants once more practised random
  generation, but this time for five separate 22 s
  blocks. These data were tape-recorded and used as
  a measure of single task control performance for
  random generation.
• Finally the matrix/verbal task was performed
  alone for five sentence sets as a final practice.
  As before, these sentences were different from
  those used in the main experiment.
• In the dual task conditions, the secondary tasks
  commenced just before presentation of the first
  sentence for the primary task, and stopped just
  after the last sentence had been heard. The
  metronome was also stopped during the recall
  period. The experimental session lasted about two
  hours for each participant, including a 15-minute
  rest break after the completion of two
  experimental conditions.

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Procedure

• The participants were first asked to fill out a
  questionnaire on their cola consumption habits
  and brand preferences. The colas were presented
  to the participants individually in an
  experimental room that was kept dimly lighted to
  eliminate possible visual cues. Instructions were
  as followsI would like to have you taste and
  identify some cola drinks. I will place two cups
  at a time in front of you, one on your left and
  one on your right. Taste these two colas in any
  order you wish then tell me what brand you think
  each one is. Be careful not to change the
  position of the cups while you are tasting them
  that is, keep the left cup on the left, and right
  cup on the right. Each time you finish with one
  pair of cups, rinse your mouth well by taking a
  few swallows of water from the water cup. When
  you have done this, I will give you the next
  pair.There are three colas involved in this
  study, Coca Cola, Pepsi Cola, and Royal Crown.
  Even if you are not sure of the brand in some
  cases, I still want you to tell me what brand you
  think it is. The two members of a pair are always
  different brands that is, a brand is never
  compared with itself. Are there any questions?
• In total, six pairs of beverages were presented
  to each participant, one pair at a time. The
  participants were exposed to each brand four
  times for a total of 12 judgments. The order of
  presentation of stimulus pairs was randomly
  determined for each participant.

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Write-up

• Title
• Method with subsections
• Design Participants Apparatus/Materials/
  Procedure
• Results
• AppendixNote whether you are a.m. or p.m.
• Hand in by Wednesday 15th October 13.00 to office
  (17.00 for blackboard)