{"id":1726,"date":"2021-05-01T23:59:16","date_gmt":"2021-05-01T23:59:16","guid":{"rendered":"https:\/\/www.musicianscience.org\/?p=1726"},"modified":"2021-05-02T00:56:44","modified_gmt":"2021-05-02T00:56:44","slug":"singing-the-dallas-theme-tune-to-yourself-is-a-right-brained-affair","status":"publish","type":"post","link":"https:\/\/www.musicianscience.org\/index.php\/singing-the-dallas-theme-tune-to-yourself-is-a-right-brained-affair\/","title":{"rendered":"Imagining the “Dallas” theme tune is a right-brained affair"},"content":{"rendered":"\n
\"\"<\/figure><\/div>\n\n\n\n

Title of paper under discussion<\/strong><\/p>\n\n\n\n

When That Tune Runs Through Your Head: A PET Investigation of Auditory Imagery for Familiar Melodies<\/p>\n\n\n\n

Authors<\/strong><\/p>\n\n\n\n

Andrea R. Halpern and Robert J. Zatorre<\/p>\n\n\n\n

Journal<\/strong><\/p>\n\n\n\n

Cerebral Cortex, Vol. 9, No. 7, pp. 697-704 (Oct 1999)<\/p>\n\n\n\n

Link to paper<\/a> (free access)<\/strong><\/p>\n\n\n\n

<\/p>\n\n\n\n

Quick summary<\/strong><\/p>\n\n\n\n

Here are four of this paper\u2019s most important conclusions:<\/span><\/p>\n\n\n\n

1) Just as visual imagination excites visual cortex<\/em> (the brain area processing \u2018real\u2019 vision), auditory imagination was found to excite auditory cortex<\/em> (the brain area processing \u2018real\u2018 sound). But whereas visual imagination often involves primary<\/em> visual cortex, the brain’s starting point for \u2018real\u2019 visual processing, auditory imagination in this experiment involved merely secondary<\/em> auditory cortex, a brain region underpinning ‘down-the-line’, but not the first stages of, \u2018real\u2019 auditory processing.<\/span><\/p>\n\n\n\n

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(image from here<\/a><\/span><\/em>)<\/figcaption><\/figure><\/div>\n\n\n\n

2) Unlike previous studies into imagining songs<\/em> – which had found activity in the left and right<\/em> hand sides of the brain – these researchers used wordless<\/em> tunes<\/em> (e.g. Beethoven Fifth or “Dallas” theme tune), and found activation mainly on the right<\/em> side of the brain, strengthening the theory that verbal processing is more left-brained and musical processing more right-brained.<\/span><\/p>\n\n\n\n

3) long-term verbal \u2018semantic\u2019 memory (eg knowing the names of colours, capital cities etc) is commonly reckoned to be a left-brain function; but this paper\u2019s results suggest that musical<\/em> semantic memory (eg knowing a familiar tune) is more right-brained.<\/span><\/p>\n\n\n\n

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The brain is divided into two hemispheres, left and right<\/span><\/em><\/figcaption><\/figure><\/div>\n\n\n\n

4) The Supplementary Motor Area, responsible for movement coding, is involved in musical imagination – is, the authors wonder, pretend-singing taking place when you imagine a tune?<\/span><\/p>\n\n\n\n

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Supplementary Motor Area (shown in green) in this animation of a sliced brain! (by Daniel Sabinasz<\/a>)<\/span><\/em><\/figcaption><\/figure><\/div>\n\n\n\n

Overview<\/strong><\/p>\n\n\n\n

Using Positron Emission Tomography (PET) to scan for brain activity, Halpern and Zatorre asked listeners in the scanner to undergo three experiments. In Experiment 1 they were asked just to listen to an unfamiliar tune. In Experiment 2 they heard the opening of a familiar tune (eg the \u2018Dallas\u2019 theme tune) and were then asked to imagine its continuation. And in Experiment 3 they listened again to an unfamiliar tune and were then asked them to imagine its repetition.<\/p>\n\n\n\n

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PET scanner<\/span><\/em><\/figcaption><\/figure><\/div>\n\n\n\n

In a bid to work out which parts of the brain were responsible for particular activities – retrieving<\/strong> a<\/strong> familiar<\/strong> melody (from long-term \u2018semantic\u2019 memory), retrieving<\/strong> an<\/strong> unfamiliar<\/strong> melody (from short-term \u2018working\u2019 memory), and imagining<\/strong> a familiar\/unfamiliar melody – the authors compared the scans from expt 1, expt 2 and expt 3, variously \u2018subtracting\u2019 the brain activity present in one from that in another, reasoning that:<\/p>\n\n\n\n

1) \u2018scan 2\u2019 minus \u2018scan 1\u2019 would reveal the brain activity behind retrieving<\/strong> a<\/strong> familiar<\/strong> melody (from long-term \u2018semantic\u2019 memory) plus imagining<\/strong> it.<\/p>\n\n\n\n

2) \u2018scan 2\u2019 minus \u2018scan 3\u2019 would reveal the activity behind retrieving<\/strong> a<\/strong> familiar<\/strong> melody (from long-term \u2018semantic\u2019 memory).<\/p>\n\n\n\n

3) \u2018scan 3\u2019 minus \u2018scan 1\u2019 would reveal the activity behind retrieving<\/strong> an<\/strong> unfamiliar<\/strong> melody (from short-term \u2018working\u2019 memory) plus imagining<\/strong> it.<\/p>\n\n\n\n

By making these comparisons the authors were able to suggest that: 1) the retrieval of musical long-term semantic memory largely involves areas in the right Frontal Lobe and \u2018secondary auditory\u2019 areas in right Superior Temporal Gyrus 2) the retrieval of musical short-term working memory is based more in the left Frontal Lobe, and 3) imagining a melody, whether familiar or unfamiliar, involves the Supplementary Motor Area.<\/p>\n\n\n\n

Introduction<\/strong><\/p>\n\n\n\n

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Andrea Halpern (lead author)<\/span><\/em><\/figcaption><\/figure><\/div>\n\n\n\n

The difference in brain activity between the act of performing and the act of imagining has long intrigued neuroscientists. Most research pre-dating this paper had focussed on visual imagination, revealing that it commonly engages all areas of the visual cortex, and is processed on both sides of the brain (the left perhaps more when the visual images are nameable, and the right more when they are complex).<\/p>\n\n\n\n

Research on patients with brain damage had shown that musical perception and imagery both rely more on the right Temporal Lobe of the brain than the left. Further research using Positron Emission Tomography (PET) scanning revealed many different brain areas \u2018lighting up\u2019 whilst people carry out musical imagination tasks; but such tasks involve many different steps, including long term \u2018semantic\u2019 recall and short-term \u2018working memory\u2019, so it wasn\u2019t clear which brain areas were exactly responsible for what.<\/p>\n\n\n\n

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Robert Zatorre, co-author<\/span><\/em><\/figcaption><\/figure><\/div>\n\n\n\n

Halpern and Zatorre addressed this lack of specificity by coming up with a 3-part experiment designed to tease apart three different strands of brain activity involved in musical imagination: semantic retrieval (of a familiar tune), working memory (of an unfamiliar tune) and image generation. The three experiments (see Method below) involved the participant 1) imagining the continuation of a familiar tune 2) listening to an unfamiliar tune, and 3) imagining the repetition of an unfamiliar tune. A comparison of the brain activity induced by each of these tasks would variously reveal, reasoned the researchers, the brain areas responsible for musical semantic retrieval, musical working memory and generation of musical imagery.<\/p>\n\n\n\n

[In order to investigate brain activity specifically associated with musical<\/em> processing they decided to work with non-verbal<\/em> tunes, noting that verbal processing (including verbal semantic retrieval) tends to be a left-brain activity, whereas musical processing is more right-brained.]<\/p>\n\n\n\n

Method<\/strong><\/p>\n\n\n\n

Eight volunteers, all musically trained, each underwent a three-experiment session in a PET scanner. In the first experiment (called \u2018Control\u2019) the participant simply listened to an unfamiliar melody.<\/p>\n\n\n\n

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example of unfamiliar melody used for Control experiment<\/span><\/em><\/figcaption><\/figure><\/div>\n\n\n\n

In the second (called \u2018Cue\/Image’) they listened to the opening few notes of a familiar melody and were asked to continue that melody \u2018in their head\u2019.<\/p>\n\n\n\n

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example of familiar melody used for Cue\/Image experiment<\/span><\/em><\/figcaption><\/figure><\/div>\n\n\n\n

In the third (called \u2018Control\/Image’) they listened again to an unfamiliar melody and were asked to repeat it \u2018in their head\u2019.<\/p>\n\n\n\n

Results<\/strong><\/p>\n\n\n\n

As outlined in the \u2018Overview\u2019 above, the authors compared the scans from expt 1 (\u2018Control\u2019), expt 2 (\u2018Cue\/Image) and expt 3 (Control\/Image\u2019), variously \u2018subtracting\u2019 the brain activity present in one from that in another. Taking the comparisons one at a time:<\/p>\n\n\n\n

1) The comparison \u2018Cue\/Image\u2019 scan minus \u2018Control\u2019 scan would, reasoned the authors, reveal the brain activity behind retrieving<\/strong> a<\/strong> familiar<\/strong> melody (from long-term \u2018semantic\u2019 memory) plus imagining<\/strong> it.<\/p>\n\n\n\n

Here is that brain activity:<\/p>\n\n\n\n

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The areas \u2018lighting up\u2019 here include the Inferior Frontal Gyrus (Inf F), an area of \u2018secondary auditory cortex\u2019 in the right Superior Temporal Gyrus (STG), and the Supplementary Motor Area (SMA). Most of this activity is on the right side of the brain.<\/p>\n\n\n\n

2) ‘Cue\/Image\u2019 scan minus \u2018Control\/Image\u2019 scan would, reasoned the authors, reveal the activity behind retrieving<\/strong> a<\/strong> familiar<\/strong> melody (from long-term \u2018semantic\u2019 memory).<\/p>\n\n\n\n

Here is that brain activity:<\/p>\n\n\n\n

\"\"<\/figure><\/div>\n\n\n\n

The areas lighting up in this comparison were similar to ‘Cue\/Image minus Control’ above [including the right Inferior Frontal Gyrus (Inf F) and an area of \u2018secondary auditory cortex\u2019 in the right Superior Temporal Gyrus(STG)]. But note there was a difference: no activation of the Supplementary Motor Area.<\/p>\n\n\n\n

3) The comparison \u2018Control\/Image\u2019 scan minus \u2018Control\u2019 scan would, reasoned the authors, reveal the activity behind retrieving<\/strong> an<\/strong> unfamiliar<\/strong> melody (from short-term \u2018working\u2019 memory) plus imagining<\/strong> it.<\/p>\n\n\n\n

Here\u2019s that brain activity:<\/p>\n\n\n\n

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Notably lighting up here is left Midfrontal Cortex\u2019 (Mid F) and, as in the \u2018Cue\/Image minus Control\u2019 comparison, Supplementary Motor Area (SMA).<\/p>\n\n\n\n

Discussion<\/strong><\/p>\n\n\n\n

Breaking the tasks down into their various components (semantic musical retrieval, working musical memory, and generating musical imagery) the authors found, by comparing the three scan subtractions above, that:<\/p>\n\n\n\n